jsbains [at] ucalgary [dot] ca
Office: HSC 2113 (403) 220-7585
Lab: HSC 2077 (403) 210-9307
The goal of my lab is to understand how physiological and behavioural challenges lead to long-term changes in neural circuitry. We focus on neurons that coordinate an organism's response to stress, with a particular interest in clarifying how the molecules released at the onset of a stressful stimulus leave a lasting imprint on how ‘stress-relevant' ciruitry functions. Within this context, we conduct experiments that will allow us to understand the fundamental rules that govern cell to cell communication within the hypothalamus and elucidate the molecular machinery that contributes to changes in synaptic function which, in turn, may be critical for changing network output.
We are currently exploring three lines of investigation:
- We have demonstrated that glial cells can permanently increase the strength of excitatory, glutamatergic synapses in the paraventricular nucleus of the hypothalamus. We are now focused on elucidating the extent of this novel interaction between glial cells and neurons and will examine the role of this interaction during physiological challenges.
- Based on new observations that homeostatic set points in vivo are defended by metaplastic synaptic changes, we are now exploring additional mechanisms through which the activity-dependent release of retrograde signals impacts synaptic transmission.
- The inhibitory synapses onto neuroendocrine parvocellular neurons, the "command" neurons of the stress axis, exhibit remarkable state-dependent plasticity. We have shown that the onset of stress is accompanied by a loss of GABA inhibition due to a collapse of transmembrane chloride gradients. We are now pursuing the cellular and molecular mechanisms that underline this remarkable switch. Furthermore, we are exploring the impact of repetitive stress on synaptic function/plasticity in this system.
We use a number of experimental techiques to answer the above questions. These include, but are not limited to: patch clamp recordings from neurons in brain slices for the measurement of excitatory and inhibitory synaptic currents; UV laser uncaging of bioactive molecules; immunohistochemistry for the labeling of receptors and neuronal subpopulations.
Key words describing research:
synaptic transmission, synaptic plasticity, stress, electrophysiology, patch-clamp, synapse, glia, neuron, GABA, glutamate, hypothalamus, neuroscience
patch clamp recordings from neurons in brain slices, UV laser uncaging of bioactive molecules, immunohistochemistry, in vivo microinjection, behavioural manipulations and hormone assays
Canadian Institutes of Health Research (CIHR)
Heart & Stroke Foundation of Canada (HSFC)
Tara Miller, millert [at] ucalgary [dot] ca (403) 220-6617
Cheryl Sank, Research Technologist sank [at] ucalgary [dot] ca
Adrienne Benediktsson, PhD, Postdoctoral Fellow almbened [at] ucalgary [dot] ca
Wataru Inoue, PhD, Postdoctoral Fellow winoue [at] ucalgary [dot] ca
Brent Kuzmiski, PhD, Postdoctoral Fellow jbkuzmis [at] hotmail [dot] com
Karl Iremonger, PhD Graduate student kjiremon [at] ucalgary [dot] ca
Jaclyn Wamsteeker, PhD Graduate student jiwamste [at] ucalgary [dot] ca