title: Adolescent maturation of inhibitory inputs onto cingulate cortex neurons is cell-type specific and TrkB dependent.
abstract: The maturation of inhibitory circuits during adolescence may be tied to the onset of mental health disorders such as schizophrenia. Neurotrophin signaling likely plays a critical role in supporting inhibitory circuit development and is also implicated in psychiatric disease. Within the neocortex, subcircuits may mature at different times and show differential sensitivity to neurotrophin signaling. We measured miniature inhibitory and excitatory postsynaptic currents (mIPSCs and mEPSCs) in Layer 5 cell-types in the mouse anterior cingulate (Cg) across the periadolescent period. We differentiated cell-types mainly by Thy1 YFP transgene expression and also retrobead injection labeling in the contralateral Cg and ipsilateral pons. We found that YFP- neurons and commissural projecting neurons had lower frequency of mIPSCs than neighboring YFP+ neurons or pons projecting neurons in juvenile mice (P21-25). YFP- neurons and to a lesser extent commissural projecting neurons also showed a significant increase in mIPSC amplitude during the periadolescent period (P21-25 vs. P40-50), which was not seen in YFP+ neurons or pons projecting neurons. Systemic disruption of tyrosine kinase receptor B (TrkB) signaling during P23-50 in TrkBF616A mice blocked developmental changes in mIPSC amplitude, without affecting miniature excitatory post synaptic currents (mEPSCs). Our data suggest that the maturation of inhibitory inputs onto Layer 5 pyramidal neurons is cell-type specific. These data may inform our understanding of adolescent brain development across species and aid in identifying candidate subcircuits that may show greater vulnerability in mental illness.
authors.affiliation: Neuroscience Graduate Program, University of California San Francisco, CA, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Vandenberg
authors.affiliation: Department of Psychology, University of California Berkeley, CA, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Piekarski
authors.affiliation: Department of Psychology, University of California Berkeley, CA, USA.
authors.forename: Natalia
authors.initials: N
authors.lastname: Caporale
authors.affiliation: Department of Pharmacology, University of Maryland Baltimore, MD, USA.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Munoz-Cuevas
authors.affiliation: Department of Psychology, University of California Berkeley, CA, USA ; Helen Wills Neuroscience Institute, University of California Berkeley, CA, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Wilbrecht
mesh_terms: D000375:Aging; D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000254:growth & development* / Q000502:physiology*; D053444:Inhibitory Postsynaptic Potentials / Q000502:physiology; D008297:Male; D051379:Mice; D009433:Neural Inhibition / Q000502:physiology*; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D020813:Receptor, trkB / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D020813:Receptor, trkB
keywords: GABA; cell type specificity; miniature post-synaptic currents; mouse; prefrontal cortex