Dopamine/Tyrosine Hydroxylase Neurons of the Hypothalamic Arcuate Nucleus Release GABA, Communicate with Dopaminergic and Other Arcuate Neurons, and Respond to Dynorphin, Met-Enkephalin, and Oxytocin

• DOI: 10.1523/jneurosci.0293-15.2015
• Publication Date: 2015-11-11T17:28:41Z
• Authors: Xiaobing Zhang; Anthony N. van de...
• Keywords: Bursting

We employ transgenic mice with selective expression of tdTomato or cre recombinase together optogenetics to investigate whether hypothalamic arcuate (ARC) dopamine/tyrosine hydroxylase (TH) neurons interact other ARC neurons, how they respond neuropeptides, and test these cells constitute a single homogeneous population. Immunostaining dopamine TH antisera was used corroborate targeted transgene expression. Using whole-cell recording on large number ( n = 483), two types different electrophysiological properties were identified in the dorsomedial where 94% contained immunoreactive dopamine: bursting nonbursting neurons. In contrast rat, regular oscillations mouse depend mechanism involving both T-type calcium A-type potassium channel activation, but are independent gap junction coupling. Optogenetic stimulation using recombinase-dependent ChIEF-AAV-DJ expressed evoked postsynaptic GABA currents majority neighboring nondopamine suggesting for first time substantial synaptic projections from Numerous met-enkephalin (mENK) dynorphin-immunoreactive boutons appeared contact mENK inhibited neuron through G-protein coupled inwardly rectifying mediated by δ μ opioid receptors. Dynorphin-A activating κ Oxytocin excited These results reveal complexity that communicate extensively within ARC. SIGNIFICANCE STATEMENT Here, we show great nucleus synthesize also contain dopamine, either electrical activity. Unlike rats, underlying not dependent junctions required activation. Neuropeptides dynorphin whereas oxytocin them. Most ventrolateral did TH-containing release onto unidentified only control pituitary hormones may modulate nearby