Bruker’s Satellite Event at Neuroscience 2026

Measuring synaptic efficacy and defining the rules for induction of synaptic plasticity at identified connections in the mammalian brain is essential for understanding how synaptic connections contribute to learning and memory. I will describe new optical approaches for selectively evoking presynaptic activity and measuring postsynaptic responses from identified pre- and postsynaptic neurons over long periods in vivo. These approaches harness all-optical interrogation – simultaneous two-photon imaging and two-photon optogenetics – to perform targeted stimulation of functionally characterized neuronal ensembles and read out synaptic efficacy. These approaches now enable dissection of synaptic plasticity mechanisms during behavioral learning.

Speaker: Michael Häusser, Ph.D.

Date: November 14, 2026
Time: TBD
Location: The Westin DC Downtown: Rock Creek Ballroom A

Adaptive behavior requires neural circuits to maintain stable representations of important environmental states while remaining flexible enough to update those representations when conditions change. In this study, we used the Inscopix nVoke system to directly examine how dorsolateral striatal cholinergic interneurons (CINs) regulate neural ensemble dynamics during threat learning and extinction.

The nVoke platform allowed us to combine single-cell calcium imaging of dorsolateral striatal neuronal populations with simultaneous optogenetic activation of local CINs in freely behaving mice. Using this approach, we found that increasing cholinergic activity did not simply scale overall population activity, but instead reorganized striatal ensembles into distinct excited and inhibited neuronal subpopulations. During fear conditioning, CIN activation produced larger shifts in population state space and accelerated the acquisition of conditioned fear. Importantly, the response of individual neurons to cholinergic stimulation could be predicted from their spontaneous activity patterns, suggesting that CINs recruit pre-existing functional states within the local network.

We then used longitudinal nVoke imaging to follow these ensemble dynamics as animals transitioned from fear conditioning to extinction. In control animals, dorsolateral striatal ensembles progressively updated as the threat-predictive cue no longer resulted in footshock. In contrast, optogenetic CIN activation maintained conditioning-associated cue responses and prevented the normal reorganization of population activity during extinction, accompanying persistent fear behavior.

Together, these experiments demonstrate how simultaneous optogenetic manipulation and single-cell imaging with the nVoke system can reveal causal relationships between neuromodulatory signaling, neural ensemble organization, and behavioral adaptation. Our findings identify striatal CINs as regulators of population-state transitions that can bias neural networks toward persistence rather than flexible updating of threat-related representations.

Speaker: Munir Gunes Kutlu, Ph.D.

Date: November 14, 2026
Time: TBD
Location: The Westin DC Downtown: Rock Creek Ballroom A

I will present an all-optical approach combining deep-brain two-photon calcium imaging with holographic optogenetic stimulation to dissect valence processing in the basolateral amygdala. Selective reactivation of appetitive and aversive ensembles biases consummatory behavior and suppresses opposing ensembles, motivating investigation of the underlying inhibitory circuitry. I will then describe recent work using microprism imaging and targeted photostimulation to probe somatostatin-expressing (SST) interneuron connectivity. Initial results show that sparse SST activation suppresses nearby water-responsive neurons, with spatial relationships consistent with local inhibitory connectivity. Together, these studies link the causal influence of neural ensembles to inhibitory microcircuit organization in behaving mice.

Speaker: Sean Piantadosi, Ph.D.

Date: November 14, 2026
Time: TBD
Location: The Westin DC Downtown: Rock Creek Ballroom A