[Abstract Title]. - Society for Neuroscience

induction protocol does not result in endocannabinoid release. The basic physiological
characteristic properties of medium spiny neurons are comparable between the genotypes. We
hypothesized that in WT mice the LTD induced by high frequency stimulation is dependent on a
coincident D2 receptor-induced reductions in AC5 activity and cAMP levels. Including 1 mM
cAMP in the internal solution in WT recordings, which prevents the postsynaptic cell from
recognizing the drop in cAMP produced by D2 receptor activation, changed the plasticity
induced by high frequency stimulation on average from LTD to LTP. Overall, these experiments
suggest that dopamine regulates corticostriatal plasticity by modulating AC5 activity and cAMP
levels.
Disclosures: J.P. Britt , None; M.A. Kheirbek, None; J.A. Beeler, None; Y. Ishikawa,
None; X. Zhuang, None; D.S. McGehee, None.
Poster
274. Basal Ganglia: Transmitters and Neuromodulation II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 274.3/II28
Topic: D.15.a. Transmitters and neuromodulation
Support: CONACYT grants 60662 and 46-161-M
Title: Chronic low-level arsenic (As) exposure causes alterations in locomotor activity of mice
Authors: U. PACHECO-BARDULLAS 1 , *M. GIORDANO 1 , L. CARRIZALES 2 , J. LIMÓN-
PACHECO 1 , S. MENDOZA 1 , V. M. RODRIGUEZ 1 ;
1 Cognitive and Behavioral Neurobio., Inst. Neurobiologia, Querétaro, Qro. 7623, Mexico;
2 Facultad de Medicina, Univ. Autónoma de San Luis Potosí, San Luis Potosí, SLP, Mexico
Abstract: Arsenic is a toxic metalloid widely present in the environment. Arsenic exposure is a
health problem associated with the development of skin cancer, black foot disease, and
hypertension. Although there are few studies on the neurotoxic effects of arsenic exposure in
humans, some studies have reported decrements in IQ, and sensory and motor alterations after
chronic exposure. On the other hand, studies using rodents exposed to doses as high as 10 mg
As/kg b.w. have found alterations in locomotor activity, brain neurochemistry, behavioral tasks,
changes in sensory and motor nerves and oxidative stress. In the present study both male and
female mice (C57BL/6J) were exposed to environmentally relevant doses of arsenic such as
0.05, 0.5, 5.0 or 50 ppm of As in drinking water for four months, and locomotor activity was
assessed every month. Male mice treated with 0.5 ppm As showed increments in horizontal