System Information Sciences

Information Biology B07

  • Assis. Prof. Katsuya Uchida    
Keywordsbrain, hormone, integrative functions, sex difference

Understanding new role of hormones on neuronal signal transduction in the central nervous system

Inside our brain, neuronal information is transmitted using electronic signals. In the nerve ending (axon terminal), electronic signals are exchanged to chemical signals, and neurotransmitters like glutamate and GABA are released from axon terminal to synapse. Thus, nerve cells communicate with another neurons via chemical signals. Recent years, it has been reported that hormones act on neurons as to neuromodulator.

We take notice of new role of hormones in the central nervous system, especially corticotropin-releasing factor (CRF) as a neuromodulator and thyroid hormone as a control factor for organogenesis. Genetically modified animals play an essential role in analyzing novel functions of hormones in the brain. We found that CRF-expressing neurons in the bed nucleus of the stria terminalis (BNST) show female-biased sexual dimorphism in last year (Uchida et al., Biology of Sex Differences 2019), and the findings of this study could not be achieved without using genetically modified animals. How does sex differences in CRF- expressing neurons in the BNST affect individual behavior? It is well known that the function of BNST with the central amygdala participate in expression of emotional behavior in the rodents and human. Therefore, sex differences of CRF-expressing neurons in the BNST would be expressed as sex differences of behavioral expression. To address this question, we need to artificially regulate specific neurons and to individually validate neuronal network in the brain. In our laboratory, we study new role of hormones in the central nervous system using advanced genetical technique.

  • Uchida et al., Biology of Sex Differences (2019) : Confocal images showing Venus and Crf in the dorsolateral BNST. The Venus and Crf are shown as green and res, respectively. The lower panel shows a merged image of Venus and Crf. Scale bar = 100 µm.

  • Uchida eta al., Neuroscience Letters (2014) : PV-positive interneurons in the neocortex of the growth-retarded mouse which shows dysfunction of thyroid stimulating hormone receptor. Photomicrographs show PV-positive interneurons in the neocortex of normal (A), grt (B), and T3-treated grt mice (C). Scale bar = 500 µm. The region of the photomicrograph indicated by the box is shown on the right as a magnified image (A′-C′).