The transfer of retinal signals from the dorsal lateral geniculate nucleus (dLGN) to the primary visual cortex (V1) is modulated by a variety of extraretinal inputs, including extrinsic connections formed by GABAergic neurons in the pretectum (PT) and visual sector of the thalamic reticular nucleus (vTRN), as well as the intrinsic connections of GABAergic dLGN interneurons. In the current study, we determined how GABAergic PT projections to the dLGN and vTRN can influence retinogeniculate transfer using a variety of viral tracing techniques, electron microscopy, in vitro physiological recordings, and optogenetics in male and female mice. We found that the PT provides over 75% of the GABAergic and over 30% of the total synaptic input to the vTRN. Optogenetic activation of PT terminals reduced the firing frequency of vTRN neurons as well as the amplitudes of their postsynaptic responses to V1 input. In the dLGN, synaptic terminals originating from the PT targeted interneurons more freque

The nature of motor deficits in Parkinson disease (PD) and aspects of their improvements with ʟ-DOPA replacement therapy (LDRT) offer potential insights into striatal dopamine actions. The defining and most LDRT responsive feature of PD, bradykinesia, is a complex phenomenon exhibiting impairments of both simple and complex limb movements. LDRT significantly remediates the former but not the latter. LDRT pharmacodynamics has two major components, the Short Duration Response (SDR), with a time course of seconds to minutes, and the Long Duration Response (LDR), with a time course of days to weeks. LDRT pharmacodynamics suggests different striatal dopamine actions on different time scales. While many studies used PD subjects to investigate striatal dopamine actions, few take LDRT pharmacodynamics into account. Correlating bradykinesia features and LDRT pharmacodynamics with our present understanding of striatal dopamine actions suggests that LDRT failure to improve complex movement perfor

Exploring the Function of Hippocampal Oscillations Tomomi Sakairi, Masanori Kawabata, Alain Rios, Yutaka Sakai, and Yoshikazu Isomura (see article e0080252025) Hippocampal oscillations called sharp-wave ripples (SWRs) occur during eating, drinking, and periods of behavioral immobility. However, studies have not examined whether SWRs are involved during slowed movement prior to consummatory behaviors (i.e., stopping to lick food or water). Herein, Sakairi et al. assessed SWRs in immobilized rats that were trained to hold pedals and release them to receive water, …