Sex hormonal control of the rat somatosensory cortex

• Applicant: Professor Dr. Michael Brecht
• Subject Area: Cognitive, Systems and Behavioural Neurobiology ; Molecular Biology and Physiology of Neurons and Glial Cells
• Term: from 2018 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 397747358

The primary objective of this proposal is to determine the nature and extent to which sex hormones influence neuronal activity, development and behaviors mediated by the somatosensory cortex. The role of sex hormones in cortical information processing is essentially unknown due to the fact that classic neuroendocrinological studies have focused almost entirely on subcortical structures. It has long been known, however, that sex hormone receptors are present in the forebrain and that they can have major impact on cellular properties such as spine turnover. Our own work points to a major role of sex hormones in rat somatosensory cortex: (i) We observed different responses to social touch in males and females. (ii) We obtained preliminary evidence that the activity of fast-spiking interneurons varies female estrus cycle. (iii) We observed major map changes in rat genital somatosensory cortex in puberty. In addition, we conducted behavioral experiments, which showed that genital touch is a dominant social cue advancing female puberty in rats. Inspired by these findings we will pose the following four questions about sex hormones and somatosensory cortex: (1) With the help of an advanced postdoc with a background in hormone-physiology we will ask, what are the cellular underpinnings of hormonally-driven excitability changes? (2) Is the expansion of somatosensory genital cortex during puberty under the control of sex hormones? (3) Is somatosensory genital cortex involved in the tactile initiation/advance of puberty? (4) Does cortical hormonal action control socio-sexual behavior? Our research project is most promising, because the topic is novel, the questions raised are of great behavioral significance and the application based on strong preliminary findings.

• DFG Programme: Research Grants