Synaptic integration in circuits controlling innate behaviour
Our goal is to understand how the mouse brain implements the computations that underlie innate behaviours. We aim to provide biophysically detailed descriptions of the sequence of steps that transform input, such as the sensory clue that a predator is close by, into a behavioural output, like an escape or defensive response. In particular, we are interested in understanding how synaptic signals are integrated at different stages, and in finding what are the channels and biophysical processes that determine how signals are transformed.
We perform experiments in the mouse brain in vitro and in vivo, using whole-cell patch clamp techniques and two-photon calcium imaging to record synaptic and action potential signals from individual neurons. Synaptic input is activated in vitro using two-photon neurotransmitter uncaging and optogenetics, and by using natural stimuli in vivo. To probe the role of individual circuit elements or molecules we use genetic, chemical and optical manipulations of specific targets, such as subclasses of neurons and channel types. The consequences of these manipulations are assessed at different levels, from single neuron and network processing to behaviour. The experimental findings are complemented by computational modelling, with the aim of providing a biophysical description of signal processing, as well as abstracting the key signal transformations, in order to produce realistic network models of the circuits that control innate behaviours
Currently we focus on the hypothalamic circuits that control aggressive and feeding behaviour. We are particularly interested in determining how sensory information that triggers aggressive behaviour is processed by hypothalamic neurons. In collaboration with researchers at Janelia Farm we are currently investigating how single neurons in the arcuate nucleus integrate the excitatory synaptic input that regulates feeding behaviour.
- Smith, S.L., Smith, I.T., Branco, T. and Häusser, M. (2013)
Dendritic spikes enhance stimulus selectivity in cortical neurons in vivo.
Nature 503: (7474):115-120.
- Branco, T. (2011)
Eppendorf winner. The language of dendrites.
Science 334: 615-616
- Branco, T. and Häusser, M. (2011)
Synaptic integration gradients in single cortical pyramidal cell dendrites.
Neuron 10: 885-892
- Branco,T. Clark, B.A. and Häusser, M. (2010)
Dendritic discrimination of temporal input sequences in cortical neurons.
Science 329: 1671-1675. Epub 2010 Aug 12.
- Branco, T. and Staras, K. (2009)
The probability of neurotransmitter release: variability and feedback control at single synapses.
Nat. Rev. Neurosci. 10: 373-383
- Branco, T., Staras, K., Darcy, K.J. and Goda, Y. (2008)
Local dendritic activity sets release probability at hippocampal synapses.
Neuron 59: 475-485
- Zinaida Perova