What effect does estrogen have on the sense of smell?

The study examined zebrafish embryos and identified a new type of astrocyte, named estrogen-responsive olfactory bulb (EROB) cell

The study, led by Dr Aya Takesono at the University of Exeter, used a genetically engineered (transgenic) zebrafish, developed in the laboratories of Professor Taylor and Dr Cudo at the University of Exeter, that could Microscopic imaging to visualize cells and tissues that respond to estrogen

Using this transgenic zebrafish, combining chemical and genetic methods to manipulate these estrogen-responsive cells, revealed a new function for estrogen in embryonic brain development

Dr Takesono said: "Previous studies in mice have shown that estrogen is important for the development of the brain's somatosensory cortex and for the formation of dimorphic brain tissue, which regulates reproductive function and behaviour in old age.

"In this study, however, we show that the olfactory bulb is one of the earliest parts of the developing brain to respond to estrogen in the zebrafish embryo

"We further show that our newly identified EROB cells mediate estrogen-driven instructions for the development of the olfactory system in the embryonic brain

Tracking the development of these EROBs using various cellular and imaging methods revealed that they interact with olfactory sensory neurons and that their loss or disturbance of their interactions with peripheral neurons disrupts the establishment of inhibitory neural connections in the olfactory glomerulus

Using another transgenic zebrafish, this time examining both neural activity (by detecting calcium produced by nerve cell firing) and estrogen response, the study showed that estrogen signaling through these newly identified EROBs alters neuronal activity in the olfactory bulb, which in turn affects Odor response behavior

This study provides evidence that estrogen acts on EROB glial cells to modulate the olfactory circuit and has an important effect on later olfaction

Professor Tyler, senior author of the study, said: "The discovery of new embryonic brain cells involved in the development of olfaction in fish opens up an important new area of ​​research for us

"Surface water receives a number of man-made chemicals that mimic estrogen, and an interesting question we now hope to address is whether these chemicals affect the function of EROB glial cells during embryonic development, thereby altering the sense of smell, because this There could be significant implications for fish health

Aya Takesono, Paula Schirrmacher, Aaron Scott, Jon M.