TY - JOUR
T1 - Distinct modes of dopamine and GABA release in a dual transmitter neuron
AU - Borisovska, Maria
AU - Bensen, Ae Soon L.
AU - Chong, Gene
AU - Westbrook, Gary L.
PY - 2013/1/30
Y1 - 2013/1/30
N2 - We now know of a surprising number of cases where single neurons contain multiple neurotransmitters. Neurons that contain a fastacting neurotransmitter, such as glutamate or GABA, and a modulatory transmitter, such as dopamine, are a particularly interesting case because they presumably serve dual signaling functions. The olfactory bulb contains a large population of GABA- and dopaminecontaining neurons that have been implicated in normal olfaction as well as in Parkinson's disease. Yet, they have been classified as nonexocytotic catecholamine neurons because of the apparent lack of vesicular monoamine transporters. Thus, we examined how dopamine is stored and released from tyrosine hydroxylase-positive GFP (TH+-GFP) mouse periglomerular neurons in vitro. TH+ cells expressed both VMAT2 (vesicular monoamine transporter 2) and VGAT (vesicular GABA transporter), consistent with vesicular storage of both dopamine and GABA. Carbon fiber amperometry revealed that release of dopamine was quantal and calcium-dependent, but quantal size was much less than expected for large dense core vesicles, suggesting that release originated from small clear vesicles identified by electron microscopy. A single action potential in a TH+ neuron evoked a brief GABA-mediated synaptic current, whereas evoked dopamine release was asynchronous, lasting for tens of seconds. Our data suggest that dopamine and GABA serve temporally distinct roles in these dual transmitter neurons.
AB - We now know of a surprising number of cases where single neurons contain multiple neurotransmitters. Neurons that contain a fastacting neurotransmitter, such as glutamate or GABA, and a modulatory transmitter, such as dopamine, are a particularly interesting case because they presumably serve dual signaling functions. The olfactory bulb contains a large population of GABA- and dopaminecontaining neurons that have been implicated in normal olfaction as well as in Parkinson's disease. Yet, they have been classified as nonexocytotic catecholamine neurons because of the apparent lack of vesicular monoamine transporters. Thus, we examined how dopamine is stored and released from tyrosine hydroxylase-positive GFP (TH+-GFP) mouse periglomerular neurons in vitro. TH+ cells expressed both VMAT2 (vesicular monoamine transporter 2) and VGAT (vesicular GABA transporter), consistent with vesicular storage of both dopamine and GABA. Carbon fiber amperometry revealed that release of dopamine was quantal and calcium-dependent, but quantal size was much less than expected for large dense core vesicles, suggesting that release originated from small clear vesicles identified by electron microscopy. A single action potential in a TH+ neuron evoked a brief GABA-mediated synaptic current, whereas evoked dopamine release was asynchronous, lasting for tens of seconds. Our data suggest that dopamine and GABA serve temporally distinct roles in these dual transmitter neurons.
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U2 - 10.1523/JNEUROSCI.4342-12.2013
DO - 10.1523/JNEUROSCI.4342-12.2013
M3 - Article
C2 - 23365218
AN - SCOPUS:84873029794
SN - 0270-6474
VL - 33
SP - 1790
EP - 1796
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 5
ER -