Search bioRxiv⌕ Search

Biology subjects

Schiffino, F. L.

Publications and source records attributed to Schiffino, F. L..

2 recordsLinked to original sources

Basal forebrain parvalbumin neurons modulate vigilant attention.

Attention is impaired in many neuropsychiatric disorders1 and by sleep disruption, leading to decreased workplace productivity and increased risk of accidents2-4. Thus, understanding the underlying neural substrates is important for developing treatments. The basal forebrain (BF) is a brain region which degenerates in dementia5-7 and is implicated in the negative effects of sleep disruption on vigilance and cognition8,9. Previous studies demonstrated that the BF controls cortical fast oscillations that underlie attention10-12 and revealed the important role of cholinergic neurons13-15. However, the role of other neurochemically defined BF subtypes is unknown. Recent work has shown that one population of BF GABAergic neurons containing the calcium-binding protein parvalbumin (PV) control cortical fast oscillations and arousals from sleep16-19 but their role in awake behavior is unclear. Thus, here we test the hypothesis that BF-PV neurons modulate vigilant attention in mice. A lever release version of the rodent psychomotor vigilance test (rPVT) was used to assess vigilant attention as measured by reaction time. Brief and continuous low power optogenetic excitation of BF-PV neurons (1s,473nm@5mW) that preceded the cue light signal by 0.5s improved vigilant attention as indicated by quicker reaction times. In contrast, both sleep deprivation (8h) and optogenetic inhibition of BF-PV neurons (1s,530nm@10mW) slowed reaction times. Importantly, BF-PV excitation rescued the reaction time deficits in sleep deprived mice. These findings reveal for the first time a role for BF-PV neurons in attention. HIGHLIGHTSO_LIOptogenetic methods tested the neural circuitry of vigilant attention in mice C_LIO_LIExcitation of basal forebrain parvalbumin neurons quickened reaction times C_LIO_LISleep deprivation or inhibition of parvalbumin neurons slowed reaction times C_LIO_LIExcitation of parvalbumin neurons rescued deficits produced by sleep deprivation C_LI

neuroscience↗

Altered neural oscillations and behavior in a genetic mouse model of NMDA receptor hypofunction

IntroductionAbnormalities in electroencephalographic (EEG) biomarkers occur in patients with schizophrenia and those clinically at high risk for transition to psychosis and are associated with cognitive impairment. While the pathophysiology of schizophrenia remains poorly understood, converging evidence suggests N-methyl-D-aspartate receptor (NMDAR) hypofunction plays a central role and likely contributes to biomarker impairments. Thus, the characterization of such biomarkers is of significant interest for both the early diagnosis of schizophrenia and the development of novel treatments. MethodsWe utilized an established model of chronic NMDAR hypofunction, serine racemase knockout (SRKO) mice. In vivo EEG recording and behavioral analyses were performed on adult male and female SRKO mice and wild-type littermates to determine the impact of chronic NMDAR hypofunction on a battery of translationally-relevant electrophysiological biomarkers. ResultsSRKO mice displayed impairments in investigation-elicited gamma power that corresponded with reduced short-term social recognition. This impairment was associated with enhanced background (pre-investigation) broadband gamma activity that only appeared during social task performance. Additionally, SRKO mice exhibited sensory gating impairments, in both gamma power and event-related potential amplitude. However, other biomarkers such as the auditory steady-state response, sleep spindles, and state-specific power spectral density were generally neurotypical. ConclusionsSRKO mice provide a useful model to understand how chronic NMDAR hypofunction contributes to deficits in a subset of translationally-relevant EEG biomarkers that are altered in schizophrenia. Importantly, our gamma band findings support the hypothesis that an aberrant signal-to-noise ratio impairing cognition occurs with NMDAR hypofunction, which may be tied to impaired taskdependent alteration in functional connectivity.

neuroscience↗