title: Identification of the CART neuropeptide circuitry processing TMT-induced predator stress.
abstract: Abundance of cocaine- and amphetamine-regulated transcript (CART) neuropeptide in the limbic areas like the olfactory system, central nucleus of amygdala (CeA), ventral bed nucleus of stria terminalis (vBNST) and the hypothalamus suggests involvement of the peptide in emotive processing. We examined the role of CART in mediating fear, a strong emotion with profound survival value. Rats, exposed to 2,4,5-trimethyl-3-thiazoline (TMT), a predator related cue extracted from fox feces, showed significant increase in freezing, escape and risk assessment behavior, whereas grooming was reduced. Neuronal activity was up-regulated in the CeA and vBNST in terms of increased immunoreactivity in CART elements and c-Fos expression. Increased expression of both the markers was also seen in some discrete magnocellular as well as parvicellular subdivisions of the paraventricular nucleus (PVN). However, CART containing mitral cells in the main or accessory olfactory bulb did not respond. CART antibody was stereotaxically injected bilaterally into the CeA to locally immunoneutralize endogenous CART. On exposure to TMT, these rats showed reduced freezing, risk assessment and escape behavior while grooming was restored to normal value. We suggest that the CART signaling in the CeA and vBNST, but not in the olfactory system, might be an important component of the innate fear processing, and expression of stereotypic behavior, while CART in the PVN subdivisions might mediate the neuroendocrine response to predator stress.
authors.affiliation: Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411 008, India.
authors.forename: Anju
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411 008, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Rale
authors.affiliation: Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411 008, India.
authors.forename: Kaweri
authors.initials: K
authors.lastname: Utturwar
authors.affiliation: Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411 008, India. Electronic address: aurnab@iiserpune.ac.in.
authors.forename: Aurnab
authors.initials: A
authors.lastname: Ghose
authors.affiliation: Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411 008, India. Electronic address: subhedar@iiserpune.ac.in.
authors.forename: Nishikant
authors.initials: N
authors.lastname: Subhedar
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000008:administration & dosage; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003463:Cues; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D046352:Freezing Reaction, Cataleptic / Q000187:drug effects / Q000502:physiology*; D006120:Grooming; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009812:Odorants; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013844:Thiazoles / Q000494:pharmacology*; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
chemical_list: C451263:2,4,5 trimethylthiazoline; D057134:Antibodies, Neutralizing; D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D013844:Thiazoles; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
keywords: 2,4,5-trimethyl-3-thiazoline (TMT); Amygdala; Bed nucleus of stria terminalis (BNST); Cocaine- and amphetamine-regulated transcript (CART); Fear response; Paraventricular nucleus (PVN); Predator stress