Research Groups

  • Neural Networks and Epilepsy - Claudio Queiroz

    • This research group is interested in understanding the link between pathological oscillations and epilepsy. They have been studying the anatomical reorganization and the changes in neuronal excitability that take place in the limbic system after a brain insult. Since the epileptic brain presents major alterations in the network excitability, why is the epileptic brain not constantly seizing? What are the cellular and network alterations that give rise to epileptiform paroxysms? In which structures do these changes take place? How easily is to foresee these alterations? Once a seizure is detected, how can one abort its progression before the behavioral manifestation? These are some of the general questions with which this group is currently involved. Their major goal is the improvement of the quality of life of people with epilepsy and to unravel the mechanisms related to seizure generation in order to open new venues for symptomatological (seizure) treatments and even for the cure of the epileptic syndromes.

  • Neuro cell - Marcos Romualdo Costa

    • Our laboratory is dedicated to the study of cellular and molecular mechanisms responsible for controlling proliferation and differentiation of neural progenitors during development of the cerebral cortex and adult neurogenesis. Using contemporary techniques of molecular biology to manipulate gene expression in neural progenitors or neurons, we investigate the roles of different proteins and signaling pathways in neuronal and glial specification, as well as on neuronal survival and differentiation both in the developing brain and adult cerebral cortex after ischemic or traumatic injuries such as cerebral infarction. We also use techniques of cell transplantation to study the origins of stem cells in the adult brain and to evaluate the effect of environment on the differentiation of neural progenitors. The effects of gene manipulation and cell transplantation described above are evaluated using different techniques, including electrophysiology, behavioral and microscopic analysis. Among the later, we highlight the video time-lapse microscopy, which allows the study of various cellular phenomena in real time, both in vitro (phase contrast and fluorescence microscopy) and in situ (two-photon microscopy).

  • Neurobiology of Vision - Kerstin Schmidt

    • Neurons in early visual cortex were believed to be spatially restricted analyzers of the visual world. However, in the past years, it became increasingly clear that a single neuron's response is critically influenced by stimuli presented outside the classical receptive field. Thus, it has been proven difficult to characterize the coding of complex stimuli at the level of single neurons. Using optical imaging techniques and multi-electrode recordings, we investigate cortical representations at the population level. The comprehensive spatial information gained with the imaging technique is complemented by the temporal precision of electrophysiological recordings from previously identified cortical sites of interest. In order to investigate the contribution of different cortico-cortical circuits to cortical representations we apply reversible deactivation and microstimulation techniques.

  • Neurodynamics - Richardson Leão

    • Our group works with circuit analysis using electrophysiology and imaging. We basically employ all the 'flavours' of patch-clamp techniques (see publications), dynamic clamp and brain modelling (from single neurons to complex networks). Regarding imaging, we work with Ca2+, Na+ and voltage imaging using dyes and we recently started to express genetically encoded voltage and Ca2+ sensors in neurons. Our group's main research topic is the study of the transfer function implemented by neurons and networks of neurons with a particular focus on the contribution of oscillations in neuronal coding in the hippocampus. Our current activities include the development of a system capable to acquire and analyse field oscillations in hippocampal slices in real time. Analysed signals are then used to modulate the firing of an artificial neuron connected to a real pyramidal cell in a closed loop configuration.

  • Neurogenetics - Tarciso André Ferreira Velho

    • My laboratory is interested in understanding the genetic basis of vocal learning. We focus on the process by which songbirds acquire their vocalizations, a process analogous to the acquisition of speech in humans. To solve this issue, we have developed new technologies to generate transgenic birds. These genetically modified animals allow us to investigate the contribution of genes to the formation and functioning of the circuits involved in learning and vocal production. In addition, we have also studied the homeostatic mechanisms involved in the maintenance of stereotyped motor memories. To answer these and other questions, we use a combination of acute and chronic genetic manipulations to disrupt the activity of individual neurons or entire regions of the brain, along with imaging of calcium in behaving animals, and detailed behavioral analyzes of vocal signals.

  • Vislab - Sergio Neuenschwander

    • An influential notion in neuroscience is that the characterization of response properties of single cells is fundamental for understanding cognitive processes. In the visual system, the finding that responses are generally specific and selective to particular attributes of an object has led to the idea that neurons actually behave as detectors capable of extracting information from the outside world. According to this view, perception would be the result of encoding multiple elementary features through a modular analysis that is both parallel and hierarchical.

      Viewing the functional organization of the brain as a collection of individual cells, each performing some kind of feature extraction, belittles, however, the fact that the brain is a highly interconnected structure both within and between processing modules. A more appropriate level of description is to consider cooperative phenomena at the population level. From this perspective, the study of time dependencies in the activity between cells is of considerable interest. A number of investigations from our group and others have shown that neuronal interactions in the visual cortex exhibit high temporal precision in the millisecond range. Neurons firing in synchrony are thought to form transient ensembles...