PHD, Kent State University, 2012, College of Arts and Sciences / School of Biomedical Sciences

Social behavior is essential to an animal's survival and has been widely studied in a variety of species. All are regulated by the central nervous system and modulated by neuropeptides. One neuropeptide that is known to play a role in the regulation of social behavior is arginine vasopressin (Avp). Most of Avp's effects on behavior have been attributed to its action via its 1a receptor (Avpr1a). However, there is compelling evidence from knockout studies that the Avp 1b receptor (Avpr1b) also plays a significant role in the modulation of social behavior. Avpr1b knockout (-/-) mice show deficits in social behaviors, such as reduced aggression and impaired social recognition. The Avpr1b is more discretely distributed than the Avpr1a being found primarily in the CA2 region of the hippocampus by in situ hybridization. The presence of the Avpr1b within the CA2 region is of particular interest because animals with lesions to the hippocampus that include the CA2 region show social behavior deficits similar to that of Avpr1b -/- mice. This dissertation set out to study the role of the Avpr1b within the CA2 region of the hippocampus in the neural regulation of social behaviors, including aggression, social memory, and social motivation.

Committee: Heather Caldwell PhD (Advisor) Subjects: Behavioral Sciences; Endocrinology; Neurosciences

Master of Science, University of Akron, 2013, Biology

Vasopressin (AVP) is a neurohormone that plays a major role in regulating social behavior. While AVP regulates a number of social behaviors, its importance in the formation of pair bonds and paternal care in highly social species, such as the prairie vole (Microtus ochrogaster) and human beings, has become a major research focus. The majority of studies on AVP and the regulation of social behavior have concentrated on the role of the AVP V1a receptor (AVPR1a) subtype within the brain. However, recent studies have shown that the AVP V1b receptor (AVPR1b) subtype, also plays a significant role in the expression of social behavior, including social aggression, social motivation and social memory. Therefore, the goals of this thesis to isolated prairie vole AVPR1b, analyze its amino acid composition, localize expression within the brain and finally to compare these against known sequences and expression from polygynous rodents. In order to do this, AVPR1b RNA was extracted from the pituitary, to cDNA and sequenced. The amino acid sequence was deduced from the cDNA sequence. AVPR1b was localized through in situ hybrization histochemistry using a DIG-labeled mRNA probe containing prairie vole AVPR1b. The receptor was highly conserved showing a 92% similarity in cDNA sequence with mouse (Mus domesticus) and rat (Rattus norvegicus). The amino acid composition of the receptor was also highly conserved, showing mostly neutral substitutions with only one non-neutral substitution that occurred within the transmembrane portion of the G-coupled protein receptor. AVPR1b expression differed from rats and mice. While AVPR1b was observed in all the regions in which it has been reported in rats and mice including, the hippocampus (all regions), piriform cortex, PVN and dentate gyrus, AVPR1b was also expressed in previously unreported regions, including the oculomotor nucleus, pontine nucleus, substantia nigra and the dorsal raphe nucleus. AVPR1b has been reported in all these (open full item for complete abstract)

Committee: Bruce Cushing Dr. (Advisor); Amy Milsted Dr. (Committee Member); Qin Liu Dr. (Committee Member) Subjects: Behavioral Sciences; Biology; Endocrinology; Molecular Biology; Neurobiology