014 Diurnal changes in perineuronal nets and parvalbumin neurons in the rat medial prefrontal cortex

Abstract Introduction Perineuronal nets (PNNs) surrounding fast-spiking, parvalbumin (PV) interneurons provide excitatory:inhibitory balance within cortical circuits. This is impaired in several disorders that are also associated with altered diurnal rhythms, yet few studies examined rhythms of PNNs or PV cells. Methods We measured the intensity and number cells labeled Wisteria floribunda agglutinin (WFA) oxidative stress marker 8-oxo-deoxyguanosine (8-oxo-dG) rat prelimbic medial prefrontal cortex (mPFC) at Zeitgeber times (ZT) ZT0, 6, 12, 18. To examine changes inhibitory excitatory inputs to cells, we GAD 65/67 vGLUT1 puncta apposed without PNNs. Whole-cell slice recordings fast-spiking was conducted determine ratio alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor:N-methyl-D-aspartate receptor (AMPA:NMDA) ZT18 vs. ZT6. Finally, PV/PNN containing orthodenticle homeobox 2 (OTX2), which maintains PNNs, assessed. Results Relative intensities PNN labeling were increased dark compared light phase. The 8-oxo-dG decreased from ZT0 all times. There more on ZT6, but no puncta. an AMPA:NMDA OTX2 showed a strong trend toward increase ZT6 ZT18, differences non-PV-containing Conclusion Diurnal fluctuations alter balance. Detailed understanding how these regulated should new insights into treatments for diseases impacted by disturbances sleep circadian rhythms. Ongoing examining downstream signaling after removal. Support (if any) Washington State University Alcohol Drug Abuse Research Program, NIH GM134789 (JHH); DA033404 (BAS), DA040965 (BAS, TEB, SAA); NS078498 (JPW); P30 NS061800 (SAA); Agence Nationale de la Recherche ANR-18-CE16-0013-01 (AP AAD).