Summary
The responses of single guinea pig medial vestibular nucleus (MVN) neurons in vitro to adrenocorticotropic hormone, fragment 4–10 (ACTH4–10) were recorded extracellularly. In coronal slices and in the isolated MVN, neurons were found which responded to ACTH4–10 at picomolar concentrations (10-12M), indicating that ACTH4–10 acts directly on MVN neurons and suggesting the possibility that ACTH4–10 may act as a neurotransmitter in the MVN. In most cases where neurons responded to ACTH4–10 (37/74 neurons), the effect was a decrease in firing. Whether or not the depressive action of ACTH4–10 on the firing rate of MVN neurons in vitro is related to the acceleration of behavioral recovery from unilateral labyrinthectomy (vestibular compensation), which has been reported previously (Flohr and Luneburg 1982; Igarashi et al. 1985), is unclear.
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Darlington, C.L., Smith, F.F. & Hubbard, J.I. Guinea pig medial vestibular nucleus neurons in vitro respond to ACTH4–10 at picomolar concentrations. Exp Brain Res 82, 637–640 (1990). https://doi.org/10.1007/BF00228805
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DOI: https://doi.org/10.1007/BF00228805