Neuroscience

Neuronal circuits

Our thoughts, memories, perceptions and actions occur due to the collective activity of populations of neurons in our brain. How do a group of neurons and their synapses generate this diversity of processes?

The goal of our laboratory is to understand how circuits of neurons encode sensory stimuli, how experience modify the encoding, and which synaptic and circuit mechanisms are involved in the generation of different patterns of activity generated by different stimuli. For that we use in vivo and in vitro electrophysiological recordings, as well as optogenetics and behavioral approaches.

Processing of stimuli in the dentate gyrus of the hippocampus

The hippocampus is an area of ​​the brain whose function is related to the formation of memory and the representation of space. Virtually all areas of the hippocampus contain excitatory and inhibitory neurons that form particular micro circuits. While some patterns of connectivity between excitatory and inhibitory neurons are known, studying the functional dynamics of these connections is fundamental to understanding how the same circuit can give rise to a variety of activity patterns. In this project we want to understand how the responses of populations of neurons in the dentate gyrus of the hippocampus are reconfigured depending on the dynamics of the afferent stimuli, the neuromodulatory inputs associated with different brain states and the experience. Since the dentate gyrus is one of the few regions of the brain that produces new neurons in the adult, we investigate, in addition, the particular role that those cells have in the processing of stimuli.

Neural circuits supporting context and experience dependent representation of olfactory information

In order for neuronal circuits to adapt to a continuously changing environment, interactions between neurons should not be fixed, but ought to be able to change by experience and context. How contextual-experience affects our representation of the world is a fundamental question that is yet to be solved. In particular, which are the brain circuits that interact to form the representation of a sensory experience? In the laboratory we investigate this topic in the olfactory system. Odors can trigger strong emotional memories and, accordingly, olfactory pathways involve anatomical structures that are also heavily implicated in emotion and memory.

In this project we study the contribution of limbic areas, including the amygdala and the hippocampus, to the context, valence-signal and experience-dependent representation of odors in the olfactory cortex. For this, we perform in vivo recordings in behaving animals, as well as in vitro recordings in brain slices to investigate the circuit, cellular and synaptic mechanisms involved in those representations. In addition, by turning neurons ‘on’ and ‘off’ using optogenetic approaches, we can identify groups of neurons and brain areas that are involved in particular aspects of the behavioral task.

We believe the project can contribute to reveal fundamental principles that may be applied to contextual modulation of sensory processing in general, an important topic that we still need to understand.