Computational neuroscience, sensory processing, synaptic dynamics and plasticity
Dr. Maler’s research attempts to link the dynamics of cellular processes and the structural organization of neural networks so as to understand the emergent properties of the network. Specifically he is interested in how feedback neural architectures combined with dynamic neuronal connections (synapses) can optimize sensory processing.
Dr. Maler uses electric fish as a model system because its relatively simple nervous system permits rigorous application of theoretical methods to experimental data.
Synaptic dynamics of feedforward and feedback systems.
Brain slices are used to analyze both short term and long term synaptic plasticity. The strength of this research lies in the ability to constrain the stimulation parameters to match the known statistics of the sensory input. The molecular basis underlying these dynamics is investigated using in situ hybridization and immunohistochemistry of cloned receptor proteins from the fish, as well as pharmacological intervention. Theoretical studies include analytic and computational analysis of information transmission by dynamic synapses. (Collaborators: Rob Dunn and Andre Longtin)
Voltage-gated ion channels and neuronal dynamics.
Brain slices are used to assess the role of cloned voltage-gated channels in tuning neurons to the signal frequencies present in the animal’s environment. A major thrust of this research is to study how stereotyped temporal patterns of action potentials (spike bursts) transmit information and to investigate the interactions of synaptic input and voltage-gated ion channels in controlling these bursts. Detailed dynamical systems analysis attempts to link the biophysics of ion channels to their neural function. (Collaborators: Rob Dunn, Andre Longtin and Ray Turner)
Detection and estimation of sensory input.
In vivo recording of the activity of neurons engaged in detecting communication signals or stimuli related to the detection of prey is used to understand how intact neural networks function. Neuroethological studies of the natural behaviours of this species, and of the sensory stimuli generated during these behaviours, guide these studies. The results of the research described above is used to guide these experiments. For example, pharmacological manipulation of feedback pathways is used to probe their effects on sensory processing and the reagents are first evaluated in vitro. Information theory is used to analyze these data and link it to the underlying dynamics.
Leonard Maler received his undergraduate education at McGill University and his Graduate training at the Massachusetts Institute of Technology in the Department of Brain and Cognitive Sciences. His Doctoral Fellowship was the first analysis of the neural pathways underlying the electric sense. He did Postdoctoral Fellowships with Dr. Ted Bullock (UCSD) and at the Max Planck Institute of Biophysical Chemistry in Professor Creutzfeldt’s department. During this period he participated in developing the electric fish model of sensory processing. He joined the University of Ottawa in 1976 and was recently made a Distinguished Professor.