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Int. J. Devl Neuroscience 28 (2010) 105–109<br />
Contents lists available at ScienceDirect<br />
International Journal of Developmental Neuroscience<br />
journal homepage: www.elsevier.com/locate/ijdevneu<br />
Perinatal exposure to music protects spatial memory against callosal lesions<br />
Anca Amagdei, Felicia Rodica Balteş, Julia Avram, Andrei C. Miu *<br />
Program of Cognitive Neuroscience, Department of Psychology, Babes-Bolyai University, 37 Republicii St., Cluj-Napoca, CJ 400015, Romania<br />
ARTICLE<br />
INFO<br />
ABSTRACT<br />
Article history:<br />
Received 28 May 2009<br />
Received in revised form 21 July 2009<br />
Accepted 30 August 2009<br />
Keywords:<br />
Music<br />
Neuroprotection<br />
Spatial memory<br />
Corpus callosum<br />
Callosotomy<br />
Several studies have indicated that the exposure of rodents to music modulates brain development and<br />
neuroplasticity, by mechanisms that involve facilitated hippocampal neurogenesis, neurotrophin<br />
synthesis and glutamatergic signaling. This study focused on the potential protection that the perinatal<br />
exposure to music, between postnatal days 2 and 32, could offer against functional deficits induced by<br />
neonatal callosotomy in rats. The spontaneous alternation and marble-burying behaviors were<br />
longitudinally measured in callosotomized and control rats that had been exposed to music or not. The<br />
results indicated that the neonatal callosotomy-induced spontaneous alternation deficits that became<br />
apparent only after postnatal day 45, about the time when the rat corpus callosum reaches its maximal<br />
levels of myelination. The perinatal exposure to music efficiently protected the spontaneous alternation<br />
performance against the deficits induced by callosotomy. The present findings may offer important<br />
insights into music-induced neuroplasticity, relevant to brain development and neurorehabilitation.<br />
ß 2009 ISDN. Published by Elsevier Ltd. All rights reserved.<br />
An increasing literature has started to document the effects of<br />
music on brain development and neuroplasticity in animal models.<br />
Even compared with species-specific auditory stimuli, the exposure<br />
of chicken embryos to music induces increased volumes and neuron<br />
densities in brainstem auditory nuclei (Wadhwa et al., 1999).<br />
Indeed, developing rats that have been prenatally exposed to music<br />
also show increased hippocampal neurogenesis, as well as facilitated<br />
spatial memory (Fukui and Toyoshima, 2008; Kim et al., 2006).<br />
The effects of music on neurogenesis might be mediated by the<br />
neurotrophin synthesis in the brain. The perinatal exposure to music<br />
reduces the level of nerve growth factor (NGF), and increases the<br />
level of brain-derived neurotrophic factor (BDNF) in the hippocampus<br />
and hypothalamus of mice (Angelucci et al., 2007a,b). Music<br />
is also associated with the superior performance of mice in passive<br />
avoidance tasks (Angelucci et al., 2007a). In addition, a similar<br />
manipulation increases the levels of the BDNF-receptor, tyrosine<br />
kinase receptor B (TrkB), and 3-phosphoinositide-dependent<br />
protein kinase-1 (PDK1), which is one of the downstream targets<br />
in BDNF/TrkB signaling (Chikahisa et al., 2006). The activation of this<br />
signaling pathway correlates negatively with the number of errors<br />
that mice make in a cross-maze.<br />
Perinatal music exposure also stimulates glutamate signaling<br />
by increasing the levels of AMPA receptor GluR2 subunit in the<br />
Abbreviations: BDNF, brain-derived neurotrophic factor; CC, corpus callosum; NGF,<br />
nerve growth factor; PDK1, 3-phosphoinositide-dependent protein kinase-1; PN,<br />
postnatal day; TrkB, tyrosine kinase receptor B.<br />
* Corresponding author. Tel.: +40 264 590967; fax: +40 264 590967.<br />
E-mail address: andrei_miu@emcoglab.org (A.C. Miu).<br />
auditory cortex and cingulate gyrus of rats (Xu et al., 2007), as well<br />
as NMDA receptor NR2B subunit in the auditory cortex (Xu et al.,<br />
2009). The latter effect is also associated with increased auditory<br />
discrimination in developing rats. Finally, postnatal music<br />
exposure increases the dopamine levels in the neostriatum, which<br />
are associated with reduced systolic blood pressure in spontaneously<br />
hypertensive rats (Sutoo and Akiyama, 2004). Overall,<br />
these findings in animal models argue for the specific neurobiological<br />
effects of music exposure, which not surprisingly seem to be<br />
enhanced during brain development.<br />
Recent studies in humans show that music exposure can also be<br />
beneficial in neurorehabilitation (Sarkamo et al., 2008). Music<br />
listening is associated with facilitated recovery of verbal memory<br />
and focused attention, as well as less affective symptoms in<br />
patients with middle cerebral artery stroke (Sarkamo et al., 2008).<br />
Music also enhances visual awareness in neuropsychological<br />
patients with visual neglect, by inducing positive affect associated<br />
with the increased activation and functional coupling of the<br />
frontal, spared parietal, and occipital cortical areas involved in<br />
emotion, attention, and early vision processing (Soto et al., 2009).<br />
Similar mechanisms may contribute to the beneficial effects that<br />
learning to play musical instruments has on the motor recovery of<br />
stroke patients (Schneider et al., 2007). However, it has been<br />
acknowledged that the effects of an enriched sound environment<br />
on recovery from neural damage have only been studied in a<br />
handful of human studies and no animal models (Sarkamo et al.,<br />
2008). To our knowledge, the only relevant study in this line<br />
included music in a more general enriched environment experimental<br />
condition applied to developing rats that had undergone<br />
0736-5748/$36.00 ß 2009 ISDN. Published by Elsevier Ltd. All rights reserved.<br />
doi:10.1016/j.ijdevneu.2009.08.017
106<br />
A. Amagdei et al. / Int. J. Devl Neuroscience 28 (2010) 105–109<br />
Fig. 1. A schematic outline of the experimental design of this study. ‘‘’’ designates manipulation; ‘‘O’’ designates measurement.<br />
experimental status epilepticus (Faverjon et al., 2002). This study<br />
showed that, as part of the enriched environment, music increases<br />
the hippocampal neurogenesis and a key transcription factor (i.e.,<br />
phosphorylated cyclic AMP response element protein) in the<br />
molecular cascade of learning neuroplasticity, and facilitates<br />
spatial memory.<br />
The present study focused on the effects of perinatal exposure<br />
to music on behavioral performance in developing rats that<br />
underwent callosotomy in their first postnatal (PN) day (PN1).<br />
Based on previous suggestions that music influences behavior via<br />
mechanisms that it shares with spatial processing (Aoun et al.,<br />
2005; Cupchik et al., 2001; Rauscher et al., 1998), or facilitated<br />
emotional arousal (Thompson et al., 2001), we chose to assess<br />
spatial memory and emotional reactivity in the present study. To<br />
this purpose, the non-invasive and ethologically relevant procedures<br />
of spontaneous alternation in a T-maze (Deacon and Rawlins,<br />
2006), and marble burying (Deacon, 2006) were used. In light of<br />
previous observations that the development and functions of the<br />
corpus callosum (CC) are influenced by music (Patston et al., 2007;<br />
Schlaug et al., 1995), the present study tested the potential<br />
beneficial effects of music against neonatal callosotomy. Therefore,<br />
the design of this animal model was carefully adapted to be<br />
relevant to the human literature on music, brain and behavior.<br />
1. Experimental procedures<br />
Wistar female rats (N = 12) were allowed to mate with male rats for 24 h. One<br />
day later, females were separated from males, and housed individually under<br />
controlled temperature (20–22 8C) and light–dark cycle (light on from 07:00 to<br />
19:00). Food and water were available ad libitum. The resulting N = 57 pups were<br />
randomly distributed in four experimental groups: control; callosotomy; control<br />
+ music; and callosotomy + music. The survival rate was 96.49%, and two<br />
callosotomized animals were excluded from the analyses because they displayed<br />
signs of extracallosal damage. Therefore, the data reported here are based on the<br />
following samples: N = 14 control (7 females); N = 13 callosotomy (6 females);<br />
N = 10 control + music (6 females); and N = 16 callosotomy + music (8 females).<br />
Until PN21, the pups were housed together with their mother. Weanlings were then<br />
separated by sex and housed in groups of 3–6 animals per cage.<br />
The rats in the auditory enriched conditions were exposed to music during<br />
their active nocturnal period. A playlist that included 42 piano compositions of<br />
Wolfgang Amadeus Mozart (see Supplementary Material) was continuously<br />
played (65–75 dB) for 12 h, between 19:00 and 07:00. In contrast to other<br />
similar studies, we chose to expose rats to a wider set of musical stimuli in<br />
order to maximize their auditory enrichment, especially considering that due to<br />
their higher absolute auditory threshold, they hear about half (i.e., sounds<br />
>500 Hz, corresponding to a point between B 5 and C 5 on the keyboard) of the<br />
available piano notes in a given sonata (Steele, 2003). They are deaf to air-borne<br />
sounds (i.e., but not bone sound conduction) until PN11, but they display<br />
cochlear microphonic responses from PN2, and auditory brainstem responses<br />
from PN7–10 (Steele, 2003). The rats in the two experimental groups<br />
(control + music, and callosotomy + music) were exposed to this music each<br />
night, between PN2 and PN32 (see Fig. 1). Therefore, this developmental period<br />
starts after the neural circuit that supports hearing becomes functional, and<br />
covers the time when the myelination and functional maturation of the CC takes<br />
place in the brain of rats.<br />
In PN1, the pups underwent callosotomy or sham surgery, as described in<br />
Manhaes et al. (2003). Briefly, a small incision was made on the rat’s scalp cartilage,<br />
behind the sinusoidal lambda and over the superior colliculus. A miniscalpel was<br />
then inserted caudorostrally underneath the dorsal sagittal sinus and moved<br />
slightly downward while pulled back. Finally, a small amount of thrombin was<br />
applied near the incision to control bleeding, and the incision was then closed using<br />
acrylate glue. Neonates were placed back with their littermates in warmed cages<br />
and after approximately 12 h they were returned to their mother. For the sham<br />
surgery, the procedure was identical except that the miniscalpel was not actually<br />
inserted in the brain.<br />
The behavioral assessment was done at four time points during development<br />
(Fig. 1), which were carefully selected considering the following developmental<br />
landmarks in rats: the body volume doubles and the anatomical features of the<br />
external ear develop around PN5 in rat pups; their coat starts to develop, and motor<br />
coordination improves by PN7–12; their eyes open at PN12–14. Therefore, the first<br />
behavioral assessments were done at PN16, and followed-up at PN45, PN75 and<br />
PN104 (Baker et al., 1979).<br />
Spontaneous alternation in a T-maze and marble burying were measured<br />
according to standard protocols (Deacon, 2006; Deacon and Rawlins, 2006).<br />
Essentially, the spontaneous alternation in a T-maze measures the natural<br />
tendency of rats to alternate the choice of an arm if information concerning the<br />
arm that they previously visited is available in their spatial working memory<br />
(Clark et al., 2000; Deacon and Rawlins, 2006). In addition to being less aversive<br />
compared to other spatial memory procedures (e.g., Morris water maze),<br />
spontaneous alternation is also more sensitive to hippocampal dysfunction and<br />
AMPA receptor manipulations (Deacon and Rawlins, 2005; Reisel et al., 2002),<br />
which have also been related to the effects of music in rodents. The procedure<br />
involved a forced choice, in which the animal is placed in the start arm and<br />
allowed to enter the open arm (i.e., the other one is blocked by a guillotine door);<br />
after confined in that arm for 30 s, the animal is gently replaced in the start area,<br />
facing away from the arms; in the following free-choice phase, it is allowed to<br />
choose between the two open arms. Therefore, each trial includes a forced and a<br />
free-choice phase, and it was limited to 2 min, according to standard protocols<br />
(Deacon and Rawlins, 2006). In order to avoid experimenter and side preference<br />
biases, the experimenter was blind to the animal’s group, and the arm that was<br />
blocked during the forced choices was counterbalanced between days and<br />
groups. In addition, the rates of spontaneous alternation were corrected for<br />
response biases (Clark et al., 2000; Douglas, 1966; Miu et al., 2006). Five trials<br />
are usually sufficient for rats to develop >75% alternation rates (Dember and<br />
Richman, 1989),butinthisstudyandaccordingto(Clark et al., 2000), each rat<br />
was given two trials, separated by 2 h, each day for 5 days (10 trials total). In<br />
addition to the number of alternations, the response latencies were also<br />
recorded as general indices of sensory-motor integrity. One week before<br />
spontaneous alternation testing, rats were placed on a food restriction schedule<br />
that reduced their body weights to 80–85% of baseline and then maintained their<br />
weights at that level.<br />
Marble burying is a behavior that is also sensitive to hippocampal lesions and<br />
glutamate receptor manipulations (Bespalov et al., 2008; Deacon and Rawlins,<br />
2005; Njung’e and Handley, 1991). It is still debated whether it reflects emotional<br />
reactivity or simply species-typical digging behavior (Deacon, 2006), but recent<br />
observations that this behavior increases in response to stress (Mikics et al., 2008),<br />
and is inhibited by anxiolytics (Broekkamp et al., 1986) argue for its relationship<br />
with emotional reactivity. Essentially, the procedure involved placing a single rat in<br />
a cage filled with 5-cm deep wood chip bedding that was tamped down to make a<br />
flat surface; 12 marbles were placed in a regular pattern, with a 4-cm distance<br />
between them; the number of marbles buried with bedding during 30-min<br />
observations were recorded (Deacon, 2006).<br />
At the end of the behavioral experiments (PN110), the rats were anesthetized<br />
using Nembutal. They were killed by a transcardial perfusion–fixation procedure,<br />
their brains were removed and placed in 10% paraformaldehyde for 24 h,<br />
stereotaxically dissected, and embedded in paraffin. Twenty-micrometers thick<br />
frontal, sagittal and horizontal sections were cut using a microtome and stained for<br />
myelin, with Nissl counterstain according to the Klüver-Barrera method. All<br />
sections were analyzed using an Olympus CX41 microscope and representative<br />
sections covering the rostrum, body and splenium of the corpus callosum were<br />
selected and reconstructed.<br />
The statistical analyses of the data were carried out using analysis of variance<br />
(ANOVA) followed by post hoc tests, and corrected for multiple comparisons. The<br />
experiment conformed to European Communities Council Directive 86/609/EEC<br />
(1986), and the international guidelines for the care and use of laboratory animals<br />
(Clark and NRC Committee, 1997).
A. Amagdei et al. / Int. J. Devl Neuroscience 28 (2010) 105–109 107<br />
Fig. 2. Histological sections showing callosotomy (arrowheads in A–D), in comparison to the integer corpus callosum (insets in A–D) and complete midline transection (F;<br />
arrowheads indicate the transected corpus callosum and anterior commissure). The sagittal section in E illustrates the integrity of the hippocampal commissure in<br />
callosotomized rats, and the inset in F shows ectopic fibers located near the longitudinal fissure in a horizontal section from a callosotomized rat. Numbers in the top left<br />
corner indicate the approximate stereotaxical frontal or sagittal plane of the section. The white squares in A–D identify the areas corresponding to those represented in insets.<br />
2. Results<br />
2.1. Histological verification of the lesions<br />
The analyses of the sections indicated that all except two animals<br />
in the callosotomy groups displayed complete section of the CC.<br />
There were no discriminable differences between the lesions of the<br />
two experimental groups (i.e., callosotomy and callosotomy + music).<br />
The animals with extracallosal lesions were therefore excluded<br />
from all subsequent analyses. We carefully verified on frontal and<br />
sagittal sections that there was no damage to the hippocampal or<br />
anterior commissures (see Fig. 2A–E), the hippocampus itself, and<br />
the frontal cortex (i.e., areas that are involved in spontaneous<br />
alternation). In frontal and horizontal sections from several animals,<br />
we identified ectopic longitudinal bundles parallel to the interhemispheric<br />
line (see inset in Fig. 2F). We found no evidence of ectopic<br />
groups of neurons in the isocortex of callosotomized rats.<br />
2.2. Behavioral results<br />
A 4 (group: control vs. callosotomy vs. control + music vs.<br />
callosotomy + music) 4 (test: PN16 vs. PN45 vs. PN75 vs. PN104)<br />
repeated measure ANOVA indicated the significant main effects of<br />
group (F [3,49] = 11.64, P < 0.0001, h 2 = 0.9) and test (F [3,49] = 5.1,<br />
P < 0.01, h 2 = 0.83) on spontaneous alternation (Fig. 3). There<br />
was also a marginally significant effect of test on spontaneous<br />
alternation latencies (P = 0.051).<br />
Follow-up Student’s t-tests showed that the spontaneous<br />
alternation performance of all groups was at the chance level in<br />
the PN16 test (t [50] = 1.51, P = 0.1). The spontaneous alternation<br />
performance was significantly higher than the chance level in all<br />
subsequent tests for the two control groups (overall t [22] = 6.82,<br />
P < 0.0001, Cohen’s d = 0.8); it approached significance (P =0.053)<br />
in PN45 and reached statistical significance (t [14] = 2.3, P < 0.02,<br />
Cohen’s d = 0.76) in PNs 75 and 104 for the callosotomy + music<br />
group; and it was significantly lower than the chance level in PNs 45,<br />
75 and 104 tests for the callosotomy group. Bonferroni-corrected<br />
post hoc contrasts indicated the following overall pattern of<br />
performance in the PN45–75–104 tests (mean differences between<br />
brackets): control control + music > callosotomy + music (28%<br />
less than control, and 20.55% less than control + music) > callosotcallosotomy<br />
(30% less than callosotomy + music).<br />
Follow-up Student’s t-tests also indicated a significant difference<br />
between the spontaneous alternation latencies in PN16 test
108<br />
A. Amagdei et al. / Int. J. Devl Neuroscience 28 (2010) 105–109<br />
Fig. 3. Spontaneous alternation performance tested at four postnatal days (PN).<br />
Solid symbols represent the groups that were exposed to music, and open symbols<br />
represent those that were not exposed to music. Dashed lines represent<br />
callosotomized rats, and continuous lines represent control rats. The horizontal<br />
line in the middle of the graph shows the chance level.<br />
and the subsequent tests (t [50] = 4.3, P < 0.001, Cohen’s d = 1.18),<br />
with a mean difference of 19.28 s between the PN16 (higher<br />
latency) and the subsequent latencies. There were no statistically<br />
significant differences between the latencies in PN45, 75 and 104<br />
tests.<br />
A 4 (group: control vs. callosotomy vs. control + music vs.<br />
callosotomy + music) 4 (test: PN16 vs. PN45 vs. PN75 vs. PN104)<br />
repeated measure ANOVA found no statistically significant effects<br />
on the number of buried marbles in the marble-burying test.<br />
3. Discussion<br />
The results of this study supported our predictions that<br />
callosotomy induces spatial memory deficits, and perinatal<br />
exposure to music protects against these functional deficits in<br />
developing rats. Both effects were supported by the present<br />
longitudinal observations on rats between PN45 and PN104. In<br />
addition, these deficits were not accompanied by alterations of<br />
marble-burying behavior, or increases of response latencies in the<br />
spontaneous alternation task.<br />
Increasing evidence has shown that the neonatal callosotomy in<br />
rodents is associated with massive reorganization of long-distance<br />
cortical projections, as well as deficits in behaviors relying on<br />
interhemispheric transfer of visuo-spatial information. For<br />
instance, it was reported that this lesion induces the formation<br />
of ectopic commisural fibers crossing to the contralateral hemisphere<br />
through callosal remnants above the septum, or the<br />
anterior commisure in hamsters (Lent, 1983). The same lesion in<br />
newborn mice is associated with reduced thickness of callosally<br />
innervated cortical areas (Ribeiro-Carvalho et al., 2006), increased<br />
lateralization of rotations to the dominant side in free swimming<br />
tests (Manhaes et al., 2007), and a left side bias in paw preference<br />
tests (Manhaes et al., 2003). We previously found that callosotomy<br />
induces spontaneous alternation deficits in adult rats, which were<br />
not confounded by spatial preference biases (Miu et al., 2006).<br />
Using callosotomy and crossed lesions, subsequent studies<br />
suggested that a crossed fronto-striatal circuit underlies the<br />
performance in a more complex operant delayed alternation task<br />
(White and Dunnett, 2006).<br />
The present study contributes to this literature by showing for<br />
the first time that neonatal callosotomy is also associated with<br />
spontaneous alternation deficits. Rats that underwent callosotomy<br />
in PN1 had approximately 38% fewer spontaneous alternations<br />
than controls. This deficit was apparent after PN45, which is in line<br />
with other studies indicating that spontaneous alternation<br />
develops at above-chance levels only after PN30 in rats (Egger<br />
et al., 1973). Histological and neuroimaging studies also show that<br />
CC is visible at PN1 in rats, but its myelination starts at about PN12<br />
and reaches its maximum at PN45 (Bockhorst et al., 2008; Wiggins,<br />
1986). Therefore, it is possible that the fronto-striatal circuit<br />
underlying spontaneous alternation becomes functional after<br />
myelination of the CC reaches a critical stage. At any rate, the<br />
spontaneous alternation deficit that we induced by callosotomy at<br />
PN1 may be clinically relevant, especially considering the relative<br />
correspondence of brain development at PN7 in rats, and that of<br />
premature or full-term infants (Vannucci et al., 1999). Also, in light<br />
of the interest of perinatal callosal lesions and working memory in<br />
humans (Santhouse et al., 2002), this rat model of callosotomyinduced<br />
deficits in spontaneous alternation offers a framework for<br />
experimental investigations of the effects of controlled lesions of<br />
the CC on behaviors that depend on working memory.<br />
The other main finding of the present study is that perinatal<br />
exposure to music protects the development of spontaneous<br />
alternation against callosotomy. Previous studies have found that<br />
the effects of music on neuroplasticity in developing rats involve<br />
hippocampal (Angelucci et al., 2007a; Kim et al., 2006) and<br />
glutamate receptor-dependent mechanisms (Xu et al., 2007, 2009).<br />
Perinatal exposure to music also modulates the levels of certain<br />
neurotrophins (e.g., BDNF) in the brain (Angelucci et al., 2007b;<br />
Chikahisa et al., 2006), in a manner that is quantitatively related to<br />
spatial learning performance (Chikahisa et al., 2006). The<br />
behavioral tasks that we used in the present study are sensitive<br />
to hippocampal dysfunctions (Deacon and Rawlins, 2005; Njung’e<br />
and Handley, 1991), as well as glutamate receptor manipulations<br />
(Bespalov et al., 2008; Reisel et al., 2002). Therefore, perinatal<br />
exposure to music may have protected these behaviors against<br />
callosotomy, based on mechanisms that involve hippocampal and<br />
glutamatergic signaling. In light of the studies showing the cortical<br />
facilitation of experience-dependent neuronal growth following<br />
callosotomy in rats (Adkins et al., 2002), it is also possible that the<br />
protective effect of music that we identified in the present study is<br />
supported by a neurotrophin-dependent mechanism. However,<br />
the histological analyses included in the present study were<br />
limited and did not allow us to investigate in-depth the degree to<br />
which the protective effects of music extended to the neural level<br />
(e.g., reorganization of neural circuits). Future immunohistochemical<br />
and electron microscopic studies of the neural mechanisms by<br />
which music protects spatial memory against callosotomy would<br />
be worthwhile, especially in light of the important effect that early<br />
music exposure has on the volume of the area of the CC in humans<br />
(Schlaug et al., 1995). Moreover, this animal model may be relevant<br />
to neurorehabilitation in other pathologies, such as stroke or<br />
epilepsy (Faverjon et al., 2002; Sarkamo et al., 2008).<br />
Animal studies of music-induced neuroplasticity have borrowed<br />
from the human literature the claim that music may<br />
facilitate spatial performance either by facilitated emotional<br />
arousal, increased vigilance, or computations that music and<br />
spatial processing share (Cupchik et al., 2001; Rauscher et al.,<br />
1993; Thompson et al., 2001). The present study showed that<br />
perinatal music exposure does not influence marble-burying<br />
behavior. This behavior is increased in rats that have been exposed<br />
to stressors (Mikics et al., 2008), an effect that may indicate the<br />
sensitivity of marble burying to emotional arousal. Therefore, the<br />
results reported here suggest that music stimulates spatial<br />
information processing by mechanisms other than emotional<br />
arousal. However, this issue needs further scrutiny using more<br />
specific emotional reactivity tasks (e.g., open-field, fear conditioning),<br />
and it may turn out as a point of divergence related to the<br />
mechanisms that mediate the cognitive effects of music in animals<br />
and humans. Music may influence brain and cognition by<br />
emotional mechanisms in humans, and more general mechanisms<br />
(e.g., vigilance) in animals.<br />
In conclusion, this study offers the first evidence that neonatal<br />
callosotomy induces spatial memory deficits that become apparent
A. Amagdei et al. / Int. J. Devl Neuroscience 28 (2010) 105–109 109<br />
in developing rats after PN45. We have also shown that perinatal<br />
exposure to music offers an efficient protection against these<br />
functional deficits. These results are contributing to the developing<br />
research on the potential neuroprotective effects of music in animals<br />
and humans, with important implications for music-induced<br />
neuroplasticity and neurorehabilitation.<br />
Acknowledgements<br />
We are grateful to several colleagues from our laboratory who<br />
contributed to the behavioral measurements, and Dr. Constantin<br />
Puica (Institute of Biological Research, Cluj-Napoca) who coordinated<br />
the histological analyses. We also thank Mr. Horia Borza for<br />
help with the space required in this study. This study was<br />
supported by the Romanian Ministry of Education and Research<br />
through grants CEEX 131/2006 and 124/2006.<br />
Appendix A. Supplementary data<br />
Supplementary data associated with this article can be found, in<br />
the online version, at doi:10.1016/j.ijdevneu.2009.08.017.<br />
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