State-dependent alterations in hippocampal oscillations in serotonin 1A receptor-deficient mice.
Mice lacking the serotonin 1A receptor (5-HT(1A)R) show increased levels of anxiety-related behavior across multiple tests and background strains. Tissue-specific rescue experiments, lesion studies, and neurophysiological findings all point toward the hippocampus as a potential mediator of the phenotype. Serotonin, acting through 5-HT(1A)Rs, can suppress hippocampal theta-frequency oscillations, suggesting that theta oscillations might be increased in the knock-outs. To test this hypothesis, local field potential recordings were obtained from the hippocampus of awake, behaving knock-outs and wild-type littermates. The magnitude of theta oscillations was increased in the knock-outs, specifically in the anxiety-provoking elevated plus maze and not in a familiar environment or during rapid eye movement sleep. Theta power correlated with the fraction of time spent in the open arms, an anxiety-related behavioral variable. These results suggest a possible role for the hippocampus, and theta oscillations in particular, in the expression of anxiety in 5-HT(1A)R-deficient mice.
Gordon
Joshua A
JA
Center for Neurobiology and Behavior, Department of Psychiatry, Columbia University, New York, New York 10032, USA. jg343@columbia.edu
Lacefield
Clay O
CO
Kentros
Clifford G
CG
Hen
Rene
R
D000818:Animals; D001008:Anxiety Disorders / Q000235:genetics / Q000503:physiopathology*; D004567:Electrodes, Implanted; D004569:Electroencephalography; D005106:Exploratory Behavior / Q000502:physiology; D005163:Factor Analysis, Statistical; D006624:Hippocampus / Q000503:physiopathology*; D018782:Maze Learning; D051379:Mice; D018345:Mice, Knockout; D017966:Pyramidal Cells / Q000502:physiology; D044282:Receptor, Serotonin, 5-HT1A / Q000172:deficiency* / Q000235:genetics; D012701:Serotonin / Q000502:physiology; D016037:Single-Blind Method; D012895:Sleep, REM / Q000502:physiology
D044282:Receptor, Serotonin, 5-HT1A; D012701:Serotonin