Research Interests

Magoski laboratory - Long-term changes to neuronal excitability and secretion

Many types of neurons display the remarkable property of responding to a transient stimulus with long-term changes to activity, excitability, and/or secretion.  This form of plasticity is critical to learning, sensory coding, motor output, and neuroendocrine control.

We use electrophysiology, imaging, and molecular biology to investigate how changes to neuroendocrine cell excitability and peptide release control ovulation in the mollusc, Aplysia californica.  This marine snail has been used for almost 50 years to study the cellular and molecular basis of memory, motor pattern generation, defensive reactions, and reproduction, as well as ion channel modulation and function.


Areas of research:
• The control of excitability and secretion by voltage-gated Ca2+ channels and non-selective cation channels.
• Gap junction biophysics and modulation, as well as the role of electrical synapses in shaping neuronal bursting.

Aplysia
bag cell neurons:

• In Aplysia (pictured left), the bag cell neurons are found in two clusters in the nervous system and serve as command neurons for egg-laying behaviour.
• These neuroendocrine cells can be examined either in the intact nervous system or, more commonly, as single neurons isolated in primary culture (pictured right).


Bag cell neuron afterdischarge:
• The afterdischarge is a dramatic change in excitability brought about by the concerted action of many ion channels, second messenger systems, and kinases or phosphatases (pictured left as an ensembe extracellular recording from an intact cluster).
• Activity-dependent changes to neuronal excitability can be triggered by both Ca2+ channels and non-selective cation channels (pictured right as a membrane potential recording from a single neuron).






Ion channels:
• Of interest is a highly regulated cation channel, permeable to Ca2+, Na+, and K+ ions, that provides excitatory drive for the afterdischarge.