Infusions of muscimol into the lateral septum do not reduce rats’ defensive behaviors toward a cat odor stimulus

• Published in: Neuroscience letters Vol. 584; pp. 373 - 377
• Main Authors: Chee, San-San A., Patel, Ronak, Menard, Janet L.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.01.2015
• Subjects: Animals; Avoidance Learning - drug effects; Cat odor; Cats; Cues; Escape Reaction - drug effects; GABA-A Receptor Agonists - pharmacology; Infusions, Intraventricular; Lateral septum; Locomotion - drug effects; Male; Maze Learning - drug effects; Muscimol; Muscimol - pharmacology; Odorants; Plus-maze; Rat; Rats, Long-Evans; Septum of Brain - drug effects; Septum of Brain - physiology; Smell; Rat; Muscimol; Cat odor; Lateral septum; Plus-maze
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2014.11.005

•We tested the effects of local infusions of muscimol in two rat models of anxiety.•Muscimol into the lateral septum (LS) increased rats’ open arm activity.•The same infusions reduced rats’ head-out postures toward cat-odor collar.•However, this reduction was also present toward a control (cat-odor free) collar.•The LS does not selectively regulate rats’ defensive responses to a cat odor cue. The lateral septum (LS) is implicated in behavioral defense. We tested whether bilateral infusions of the GABAA receptor agonist muscimol into the LS suppress rats’ defensive responses to cat odor. Rats received intra-LS infusions of either saline or muscimol (40ng/rat) and were exposed to either a piece of a cat collar that had been previously worn by a cat or to a control (cat odor free) collar. Rats exposed to the cat odor collar displayed more head-out postures, while intra-LS application of muscimol reduced the number of head-out postures. However, this reduction was also present in rats exposed to a control (cat odor free) collar. This latter finding suggests that despite its involvement in other defensive behaviors (e.g., open arm avoidance in the elevated plus maze), the LS does not selectively regulate rats’ receptor defensive responding to the olfactory cues present in our cat odor stimulus.