[BIC-announce] FW: Killam Lecture - TODAY - Genetically based sensitivities for and against kindled epilepsy: Coomorbid personality attributes

[Jennifer Chew, Ms.]

PLEASE DISCARD IF THIS IS A DUPLICATE.  THANK YOU.  JENNIFER 

 

Jennifer Chew

McConnell Brain Imaging Centre

MNI - WB317

3801 University Street

Montreal, Qc  H3A 2B4

Telephone:  514-398-8554

Fax:  514-398-2975

 

 

 *****REMINDER*****

 

Killam Lecture - TODAY

 

Speaker:  Dan McIntyre, Ph.D.

Department of Psychology, Carleton University

 

Title:  Genetically Based Sensitivities for and Against Kindled
Epilepsy:  Coomorbid Personality Attributes

 

Place:  de Grandpre Communication Centre

 

Time:  4:00 pm

 

 

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Dr. Dan McIntyre

Department of Psychology
Carleton University 

Area of Research 
Dr. McIntyre's research centers on developing a fuller understanding of
the mechanisms of neuroplasticity as reflected in both epilepsy and
learning/memory. The experiments are broadly based in electrophysiology,
anatomy and behaviour. The electrophysiological work is often
accomplished in whole animals and makes extensive use of the kindling
model of epilepsy. Additional electrophysiological studies are conducted
using in vitro slice preparations of various temporal areas. Most
particularly the work concentrates on the perirhinal cortex and its
relationships both anatomically and functional with other limbic
structures, most notably the piriform and entorhinal cortices, the
amygdala and hippocampus. 

Abstract of Killam talk:

It has long been questions as to whether there is a genetic
susceptibility to temporal lobe epilepsy [TLE], a condition that the
kindling phenomenon models. To explore this question, we breed rats for
their speed (Fast) versus resistance (Slow) to amygdala kindling. The
breeding program, exercised throughout the 80's, clearly showed strong
genetic control over the rate of amygdala kindling development; indeed,
within 6 generations, there was no overlap in the distribution of
kindling rates between the Fast versus Slow amygdala kindling rat
strains.  Subsequently, these two strains have provided us with a
plethora of findings concerning many aspects of kindling; in addition,
they have shown us that many comorbid behavioral or personality
attributes are also under genetic control. It is the comorbid features
that I will primarily address in this presentation.

 For example, the Slow rats are much "smarter" than Fast rats in all
behavioral tasks (including both appetitive and fear motivated, as well
as several spatial learning variants). Part of the reason for this
learning difference is because the Fast rats show two interesting and
important behaviors often reported in epileptic children: impulsivity
and an attention deficit hyperactivity disorder- ADHD. Of course, as
there are few good genetically-based animal models for these two common
human conditions, we continue to sculpt our animal models with those two
venues in mind. Our hope is that the Fast strain ultimately will provide
a unique opportunity for new drug development against both a genetic
susceptibility to TLE and ADHD.

In the learning and memory studies, we are also examining the strains in
several tasks to further clarify their performance differences and, with
special pre-training, how can we behaviorally turn a Fast rat into to a
Slow rat ('remedial programs'). We have discovered recently several ways
to achieve these outcomes. This is similar to therapeutic approaches
that define special accommodations to assist and 'normalize' individuals
with learning deficits, particularly ADHD. Our strains have also shown
us things to look for in the human ADHD condition. For example,
traditionally it has been suggested that kids with ADHD will simply
outgrow the condition. Our rat model of ADHD (the Fast rats) is based on
adult rat behavior (patterns that are also evident, of course, in the
juveniles), and suggest the dispositions of the ADHD child remain into
adulthood but, in many individuals, are ultimately masked by learning.
When questioned about this possibility, adults with ADHD and their
behavioral therapists confirm this fact. The ADHD adults have simply
learned to cope with their long-standing problem, i.e., it has not 'gone
away' with maturation. A second phenomenon that our Fast rats have
uncovered, which is largely unpublished in the human literature, but
again patients and therapists acknowledge it, is the ability of the ADHD
patient to 'hyperfocus' on well-trained tasks. Our Fast rats first
showed this disposition in over-training paradigms. Of course, like the
ADHD humans, the Fast rats initially are very distractible, and are
easily disrupted by distracter stimuli. However, when overtrained, they
focus so intensely on the problem that distracter stimuli are completely
ignored, which is unlike normal and Slow rats, who are quite willing to
briefly investigate any new stimulus. 

 

In experiments on impulsivity (which is highly comorbid with ADHD, and
is defined behaviorally as an inability to withhold responses), we are
studying this behavior in a variety of learning paradigms, including
'go/no go', DRL and many others; however, the most potent example of the
Fast rats' impulsivity is seen in a sexual context, where they are
absolutely unable to suppress immediate approach and mounting of a
conspecific female - independent of her estrous state! Needless to say,
such interactions with non-estrous females often precipitate a great
deal of aggression. This socially inappropriate behavior by the Fast
males is never seen in normal outbred or Slow rats.

I will likely conclude the presentation with some our data on strain
differences in gene expression, data that suggest that observed
alterations in fatty acid metabolism could lead ultimately toward being
seizure-prone versus seizure resistant - and engender the comordbid
personality differences.

 

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