Possible Interaction: Gamma-Aminobutyric Acid and Neuropeptide Y

“ GABA supplementation increased FI by reducing the mRNA expression levels of FI-inhibiting neuropeptides, such as POMC, leptin, Ghrelin, and CCK, during HS and by increasing the expression of FI-stimulating neuropeptides such as AgRP and NPY.”

“Depending on the neuron in which they are expressed they mediate inhibition of release of NPY and of the neuron's classical transmitter GABA , glutamate or noradrenaline, respectively.”

“… GABA tended to quadratically enhance the serum content of GABA (23.6, 30.2, 29.8, or … mmol/L for 0, 0.8, 1.6, or 2.4 g/d, respectively), and increased neuropeptide Y , with the highest value (3.07 ng/…) for 0.8 g of GABA/d.”

“ NPY also induced a sustained increase in spontaneous GABA release in cultured cerebellar neurons.”

“Interestingly, we observed an increased proportion of spontaneous inhibitory post‐synaptic currents with slower rise times, indicating that NPY may inhibit gamma aminobutyric acid release preferentially in peri‐somatic synapses.”

“In rats, significant evidence suggest a functional and behavioral interaction between NPY and GABA mediated transmission in various brain regions, including the arcuate and paraventricular nuclei of the hypothalamus which can be important in the regulation of feeding behavior.”

“The activity of NPY is likely mediated by the presynaptic inhibition of GABA and/or NPY release from interneurons and/or efferent projection neurons of the basolateral and central amygdala.”

“Additionally, NPY reduced spontaneous and evoked synaptic glutamate release onto GABA neurons by activation of Y1 and Y5 receptors.”

“In contrast to other identified ARC cells in which NPY receptor agonists were reported to generate excitatory actions, we found that NPY consistently reduced the firing rate and hyperpolarized GABA neurons including neuroendocrine GABA neurons identified by antidromic median eminence stimulation.”

“Several lines of evidence indicate that GABA and neuropeptide Y (NPY) are functionally coupled and may interact in the regulation of fear- and anxiety-induced behavior.”

“However, we found that co-treatment of the cells by NPY and neuromediators such as NMDA or GABA strongly promoted the survival of granule neurones.”