The periaqueductal gray as a critical site to mediate reward seeking during predatory hunting

Author(s)

Mota-Ortiz, Sandra Regina ^{[1, 2]} ; Sukikara, Marcia Harumi ^{[3, 2]} ; Bittencourt, Jackson Cioni ^[1] ; Baldo, Marcus Vinicius ^[4] ; Elias, Carol Fuzeti ^{[1, 5]} ; Felicio, Luciano Freitas ^[3] ; Canteras, Newton Sabino ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, BR-05508900 Sao Paulo - Brazil

^[2] City Univ Sao Paulo, UNICID, Lab Neural Basis Behav, BR-03071000 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Vet Med, Dept Pathol, BR-05508900 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508900 Sao Paulo - Brazil

^[5] Univ Texas SW Med Ctr Dallas, Div Hypothalam Res, Dept Internal Med, Dallas, TX 75390 - USA

• Document type: Journal article
• Source: Behavioural Brain Research; v. 226, n. 1, p. 32-40, JAN 1 2012.
• Web of Science Citations: 21

Abstract

Previous studies using morphine-treated dams reported a role for the rostral lateral periaqueductal gray (rIPAG) in the behavioral switching between nursing and insect hunting, likely to depend on an enhanced seeking response to the presence of an appetitive rewarding cue (i.e., the roach). To elucidate the neural mechanisms mediating such responses, in the present study, we first observed how the rIPAG influences predatory hunting in male rats. Our behavioral observations indicated that bilateral rIPAG NMDA lesions dramatically interfere with prey hunting, leaving the animal without chasing or attacking the prey, but do not seem to affect the general levels of arousal, locomotor activity and regular feeding. Next, using Phaseolus vulgaris-leucoagglutinin (PHA-L), we have reviewed the rIPAG connection pattern, and pointed out a particularly dense projection to the hypothalamic orexinergic cell group. Double labeled PHA-L and orexin sections showed an extensive overlap between PHA-L labeled fibers and orexin cells, revealing that both the medial/perifornical and lateral hypothalamic orexinergic cell groups receive a substantial innervation from the rIPAG. We have further observed that both the medial/perifornical and lateral hypothalamic orexinergic cell groups up-regulate Fos expression during prey hunting, and that rIPAG lesions blunted this Fos increase only in the lateral hypothalamic, but not in the medial/perifornical, orexinergic group, a finding supposedly associated with the lack of motivational drive to actively pursue the prey. Overall, the present results suggest that the rIPAG should exert a critical influence on reward seeking by activating the lateral hypothalamic orexinergic cell group. (C) 2011 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 04/13849-5 - Peptidergic pathways involved in the organization of feeding behavior
• Grantee: Jackson Cioni Bittencourt
• Support Opportunities: Research Projects - Thematic Grants