Université de Fribourg

Optogenetic stimulation of basal forebrain parvalbumin neurons activates the default mode network and associated behaviors

Lozano-Montes, Laura ; Dimanico, Marta ; Mazloum, Reza ; Li, Wenxue ; Nair, Jayakrishnan ; Kintscher, Michael ; Schneggenburger, Ralf ; Harvey, Michael ; Rainer, Gregor

In: Cell Reports, 2020, vol. 33, no. 6, p. 108359

Activation of the basal forebrain (BF) has been associated with increased attention, arousal, and a heightened cortical representation of the external world. In addition, BF has been implicated in the regulation of the default mode network (DMN) and associated behaviors. Here, we provide causal evidence for a role of BF in DMN regulation, highlighting a prominent role of parvalbumin (PV)...

Université de Fribourg

Basal forebrain contributes to default mode network regulation

Nair, Jayakrishnan ; Klaassen, Arndt-Lukas ; Arato, Jozsef ; Vyssotski, Alexei L. ; Harvey, Michael ; Rainer, Gregor

In: Proceedings of the National Academy of Sciences, 2018, vol. 115, no. 6, p. 1352–1357

The default mode network (DMN) is a collection of cortical brain regions that is active during states of rest or quiet wakefulness in humans and other mammalian species. A pertinent characteristic of the DMN is a suppression of local field potential gamma activity during cognitive task performance as well as during engagement with external sensory stimuli. Conversely, gamma activity is...

Université de Fribourg

Gamma band directional interactions between basal forebrain and visual cortex during wake and sleep states

Nair, Jayakrishnan ; Klaassen, Arndt-Lukas ; Poirot, Jordan ; Vyssotski, Alexei ; Rasch, Björn ; Rainer, Gregor

In: Journal of Physiology-Paris, 2016, vol. 110, no. 1–2, p. 19–28

The basal forebrain (BF) is an important regulator of cortical excitability and responsivity to sensory stimuli, and plays a major role in wake-sleep regulation. While the impact of BF on cortical EEG or LFP signals has been extensively documented, surprisingly little is known about LFP activity within BF. Based on bilateral recordings from rats in their home cage, we describe endogenous LFP...

Université de Fribourg

Tree shrews (Tupaia belangeri) exhibit novelty preference in the novel location memory task with 24-h retention periods

Nair, Jayakrishnan ; Topka, Marlene ; Khani, Abbas ; Isenschmid, Manuela ; Rainer, Gregor

In: Frontiers in Psychology - Cognitive Science, 2014, vol. 5, p. 303

Novelty preference is pervasive in mammalian species, and describes an inherent tendency to preferentially explore novelty. The novel location memory task studied here assesses the ability of animals to form accurate memories of a spatial configuration, consisting of several identical objects placed within an arena. Tree shrews were first familiarized with a particular object configuration during...