Arginine vasopressin differentially modulates GABAergic synaptic transmission onto temperature‐sensitive and temperature‐insensitive neurons in the rat preoptic area. (22nd March 2018)

• Record Type: Journal Article
• Authors: Tang, Yu; Sun, Yan‐Ni; Xu, Run; Huang, Xiao; Gu, Shuang; Hong, Cheng‐Cheng; Liu, Mi‐Jia; Jiang, Heng; Yang, Yong‐Lu; Shi, Jing
• Is Part Of: European journal of neuroscience. Volume 47:Number 7(2018)
• Page Start: 866
• Page End: 886
• Publication Date: 2018-03-22
• Subjects: arginine vasopressin -- inhibitory postsynaptic currents -- preoptic area -- synaptic transmission -- warm‐sensitive neuron; Nervous system -- Periodicals; 612.8
• DOI: 10.1111/ejn.13868
• Languages: English
• ISSNs: 0953-816X

Abstract

Abstract: The preoptic area (POA) of the hypothalamus, containing temperature‐sensitive and temperature‐insensitive neurons, plays a key role in specific thermoregulatory responses. Although arginine vasopressin (AVP) has been shown to induce hypothermia by increasing the firing activities of warm‐sensitive neurons and decreasing those of cold‐sensitive and temperature‐insensitive neurons, the effects of AVP on POA GABAergic transmission remain unknown. Herein, inhibitory postsynaptic currents (IPSCs) of temperature‐sensitive and temperature‐insensitive neurons in POA slices were recorded using whole‐cell patch clamp. By monitoring changes in GABAergic transmission during AVP treatment, we showed that AVP decreased the amplitudes and frequencies of spontaneous IPSCs in mostly warm‐sensitive neurons and in some temperature‐insensitive neurons but increased these parameters in other temperature‐insensitive neurons. The IPSC amplitude was reduced for only cold‐sensitive neurons. RT‐PCR and Western blot analyses further confirmed the POA expression of V1a receptors and GABAA receptors, including the subunits α1, α2, α3, β2, β3 and γ2. The effects of AVP on IPSCs in temperature‐sensitive and temperature‐insensitive neurons were dependent on G proteins and intracellular Ca 2+ . AVP‐mediated modulation was associated with changes in the kinetic parameters (decay time, 10–90% rise time, half‐width). Together, these results suggest that AVP, acting via V1a receptors but not V1b receptors, differentially modulates GABAergic synaptic transmission and fine‐tunes the firing activities of temperature‐sensitive and temperature‐insensitive neurons in the rat POA. Abstract : Arginine vasopressin (AVP)‐modulated inhibitory postsynaptic currents (IPSCs) are carried by chloride ions via activated GABAA receptor. AVP suppresses spontaneous IPSCs (sIPSCs) amplitudes in temperature‐sensitive neurons. The proportions of AVP‐facilitated and AVP‐inhibited sIPSCs in temperature‐insensitive neurons are nearly the same. AVP changes the sIPSC kinetic parameters of temperature‐insensitive neuron. sIPSC modulation in preoptic area neurons by the V1a receptor is associated with G proteins and Ca 2+ .