Neal Lemon

Neal Lemon MSc 2000
BA Augustana University College, Camrose AB
MSc Neuroscience, University of Calgary 2000

Current Gig:
Neal Lemon , Ph.D., M.B.A.
Manager, Research Facilitation (Life Sciences)
Institutional Programs Division, Research Services Office, University of Calgary
Main Floor, Energy Resources Research Building (ERRB)
3512-33rd Street NW, Calgary, AB, T2L 1Y7
Tel: (403) 220-2726
naslemon@ucalgary.ca

Training
1997
BSc Psychology / Biology
Augustana University College
Camrose Alberta

1998 - 2000
MSc Neuroscience
University of Calgary
Calgary Alberta
Supervisor: Ray W. Turner

Awards
Medical Research Council Studentship

Research Focus: The ionic basis of burst discharge in electrosensory lobe pyramidal cells

Approach:

I use a combination of intracellular microelectrodes to obtain current clamp recordings in the in vitro slice preparation of Apteronotus leptorhynchus electrosensory lobe.

Preparations:

In vitro slice preparations

Below are short summaries of my projects published from the lab.

Model - Electrosensory lateral line lobe (ELL) of weakly electric fish
Pyramidal cells of the electrosensory lobe in Apteronotus leptorhynchus encode modulations in external electric fields that arise when their own emitted electric organ discharge is perturbed. My project dealt with the ionic basis for oscillatory burst discharge in pyramidal cells of one of four segmental maps of the body surface within the ELL. I use intracellular recordings in an in vitro slice preparation to determine the ionic factors underlying bursts in these principle output neurons.

Conditional backpropagation generates burst discharge in a sensory neuron
In this study we delineated a new mechanism underlying burst discharge in ELL pyramidal cells. My recordings at the somatic and dendritic level establish that these bursts arise by a "conditional backpropagation" of sodium spikes from the soma and over the proximal apical dendrites that re-excite the soma as a depolarizing afterpotential (DAP). A frequency-dependent mismatch in refractory period between soma and dendrite leads to burst discharge through a cyclic failure of backpropagation. PDF

Persistent sodium current modifies burst discharge
This study used a combination of direct intracellular recordings and drug ejections together with modeling to test the effects of persistent sodium current on the process of conditional backpropagation. We show that INaP serves to enhance the depolarization arising from the backpropagating dendritic spike, a process in turn magnified by a progressive change in dendritic spike repolarization during the burst. PDF

Peer-reviewed Publications

Lemon, N. and Turner, R.W. (2000) Conditional backpropagation generates burst discharge in a sensory neuron. J. Neurophysiology 89: 1519-1530. PDF

Doiron, B., Noonan, L., Lemon, N., and Turner, R.W. (2003) Persistent Na+ current modifies burst discharage by regulating conditional backpropagation of dendritic spikes. J. Neurophysiology 89(1): 324-337. PDF

Invited Review:
Turner R.W., Lemon, N., Doiron, B., Rashid, A.J., Morales, E., Maler, L., Longtin, and Dunn, R.J. (2002) Oscillatory burst discharge generated through conditional backpropagation of dendritic spikes. Journal of Physiology ( Paris ) 96: 517-530. PDF

Key Abstracts
Lemon, N., Lowe M., and Turner, R.W. Factors controlling oscillatory discharge in pyramidal cells of the electrosensory lateral line lobe (ELL) of weakly electric fish. Fifth Int. Congress Neuroethol., San Diego, Abst. 343, 1998.

Lemon, N. and Turner, R.W. Backpropagating spikes regulate oscillatory spike bursts. Proc Soc Neurosci 25: 455, 1999

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