The Impact of Male Sensory Cues on the Female Brain
K. M. Kendrick
Laboratory of Developmental and Cognitive Neuroscience
Department of Neurobiology, Babraham Institute, Babraham, Cambridge, CB2 4AT. UK
Contact: email@example.comThe extent to which the female's reproductive cycle influences the impact of male sensory cues on her brain and behaviour has mainly focussed on her response to actual mating. Using sheep as model we have attempted to investigate the differential effect of male visual and olfactory cues on patterns of activation in the female brain when she is sexually receptive as opposed to when she is not. Changes in neural activation were visualised in ovariectomized hormone-treated females by quantifying changes in c-fos mRNA expression after a 5 min exposure to a male. During behavioural oestrus, exposure to males significantly increased expression in all primary and association cortex regions involved with visual and olfactory processing,particularly in regions of the temporal cortex associated with face recognition. Increases also occurred in the limbic system (hippocampus CA1, subiculum, lateral septum, basolateral amygdala and bed nucleus of stria terminalis)and regions of the hypothalamus involved in mediating female sexual responses (mediobasal hypothalamus and medial preoptic area). Increased expression was also seen in the nucleus accumbens which is associated with reward. These changes occurred independent of the male intromitting and are therefore mainly due to distal male sensory cues. When the females were not sexually receptive no increased c-fos expression was seen in any cortical, limbic or hypothalamic regions excepting a small increase in temporal cortex. This occurred even though the females experienced the same level of exposure to male cues. These results demonstrate clearly that the female's reproductive cycle can dramatically alter the impact of male visual and olfactory cues not just at the level of sex hormone-concentrating neurons in the limbic system and hypothalamus but also in the primary and association cortical regions that relay sensory information to them.
Keywords: c-fos,oestrus,sheep,faces,sexual behaviour