2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

We use different antibodies to detect CREB and phosphorylated CREB (pCREB) in bee
homogenate and in fixed bee brain slices. Counterstaining of synaptic proteins and
DNA were performed to further characterize pCREB containing neurons.
pCREB immunoreactivity can be observed in a wide range of cell nuclei including
nuclei of neurons known to be involved in processing sensory information, for
example intrinsic mushroom body neurons (Kenyon cells). In contrast to the assumed
distribution of pCREB, which, as a transcription factor, is thought to be predominantly
located in the nucleus, we also find strong immunoreactivity in axonal and dendritic
parts of Kenyon cells.
We investigated the distribution of pCREB immunoreactivity in the honeybee brain in
bees with different age. We compared one day old bees with more experienced bees
and found increased pCREB levels in aged bees and, focusing on specific brain
neuropils, an ongoing redistribution and sharpening of the pCREB signal in distinct
neuronal subsets.
Since the antennal lobes and the mushroom bodies are involved in processing
sensory information, ongoing experiments focus on changes of pCREB and CREB
levels in these neuropils after learning.
����147 Jens Goldammer
Calcium imaging of retrogradely labeled retractor coxae neurons in the stick insect
Carausiusmorosus
Authors: Jens Goldammer 1 , Cathleen Rotte 1 , Joachim Schmidt 1 , Peter Kloppenburg 1 ,
Ansgar Büschges 1
Affiliation: 1 Universität zu Köln
Calcium ions (Ca2+) play an important role in various neuronal processes, e.g. release
of neurotransmitters or as 2nd messengers (for review see Berridge 1998). We are
interested in the potential contribution of Ca2+ transients to rhythmic motor activity
in stick insect leg motoneurons (MNs). Neuroanatomical data in the stick insect
Carausius morosus showed that MN neurites are mainly found in dorsal ganglion
regions, especially neurites of retractor coxae MNs that have axons in nervus lateralis
5 (nl5; Goldammer et al. 2012) and therefore are suited for calcium imaging studies.
We retrogradely labeled mesothoracic nerve nl5 with the Ca2+ sensitive dye Oregon
Green 488 Bapta-1 dextran. Measurements of Ca2+ transients in retractor coxae MNs
were combined with extracellular recordings of the antagonistic protractor coxae
MNs or of the backfilled nl5, respectively. We induced either rhythmic activity in the
MNs through application of the muscarinic receptor agonist pilocarpine (Büschges et
al. 1995) onto the mesothoracic ganglion or activity was induced by tactile
stimulation of the animal. Our results show spatially uniform Ca2+ transients in
primary neurites and higher order branches in antiphase with the activity of
excitatory protractor coxae MNs (N=5) and in-phase with activity of the labeled nl5
MNs (N=3). Currently we are investigating the role of Ca2+ transients in mediating
the tonic depolarization of MNs during walking movements.
169