Collins Stuart A, Ninan Ipe
Department of Neurosciences, University of Toledo, Toledo, OH 43614, USA.
Cereb Cortex Commun. 2021 Feb 4;2(1):tgab007. doi: 10.1093/texcom/tgab007. eCollection 2021.
The onset of several neuropsychiatric disorders including anxiety disorders coincides with adolescence. Consistently, threat extinction, which plays a key role in the regulation of anxiety-related behaviors, is diminished during adolescence. Furthermore, this attenuated threat extinction during adolescence is associated with an altered synaptic plasticity in the infralimbic medial prefrontal cortex (IL-mPFC), a brain region critical for threat extinction. However, the mechanism underlying the altered plasticity in the IL-mPFC during adolescence is unclear. Given the purported role of vasoactive intestinal polypeptide expressing interneurons (VIPINs) in disinhibition and hence their potential to affect cortical plasticity, we examined whether VIPINs exhibit an adolescence-specific plasticity in the IL-mPFC. We observed an increase in GABAergic transmission and a decrease in excitability in VIPINs during adolescence. Male mice show a significantly higher VIPIN-pyramidal neuron GABAergic transmission compared with female mice. The observed increase in GABAergic transmission and a decrease in membrane excitability in VIPINs during adolescence could play a role in the altered plasticity in the adolescent IL-mPFC. Furthermore, the suppression of VIPIN-mediated GABAergic transmission in females might be relevant to sex differences in anxiety disorders.
包括焦虑症在内的几种神经精神疾病的发病都与青春期同时出现。一致的是，在焦虑相关行为调节中起关键作用的威胁消退在青春期会减弱。此外，青春期这种减弱的威胁消退与边缘下内侧前额叶皮质（IL-mPFC）中突触可塑性的改变有关，IL-mPFC是对威胁消退至关重要的脑区。然而，青春期IL-mPFC中可塑性改变的潜在机制尚不清楚。鉴于表达血管活性肠肽的中间神经元（VIPINs）在去抑制中的假定作用以及它们影响皮质可塑性的潜力，我们研究了VIPINs在IL-mPFC中是否表现出青春期特异性可塑性。我们观察到青春期期间VIPINs中GABA能传递增加且兴奋性降低。与雌性小鼠相比，雄性小鼠的VIPIN-锥体神经元GABA能传递显著更高。青春期期间观察到的VIPINs中GABA能传递增加和膜兴奋性降低可能在青春期IL-mPFC可塑性改变中起作用。此外，雌性中VIPIN介导的GABA能传递的抑制可能与焦虑症中的性别差异有关。
