VULNERABILITY OF EXPRESSION REDUCED SERT MICE TO LEARNED HELPLESSNESS. By Jane Belyavskaya Mentor: Jeff Muller Affiliation: Columbia University (Sackler Institute of Neurobiological Sciences. Introduction. Serotonin: - key modulatory transmitter located in the
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VULNERABILITY OF EXPRESSION REDUCED SERT MICE TO LEARNED HELPLESSNESS
By Jane Belyavskaya
Mentor: Jeff Muller
Affiliation: Columbia University (Sackler Institute of Neurobiological Sciences
- key modulatory transmitter located in the
Central Nervous System
- Implicated in the regulation of certain
developmental, behavioral, and
- SSRI’s = serotonin selective reuptake
inhibitors enhance serontenergic
transmissions and decreases depression and
- s-allele: suggested in the expression
of less SERT’s, and therefore more
serotonin left in the extracellular
regions of the brain
also suggested in the prevalence of
depression and anxiety among those who
possess this gene (at odds with SSRI’s)
has let do the conclusion that serotonin
reuptake is necessary during development as
shown but fundamental KO experiment
- l-allele: suggested in the expression of
- Controls automatic
- Emotional Responses
- Hormonal Secretions
- Consolidation of New Memories
- Spatial Orientation
- mediating conflicting thoughts
- making choices between right and wrong
- predicting future events
- governing social control
People with at least one short SERT gene end up with smaller amygdalae, and even more dramatically, smaller cingulate cortices as well. Therefore there is a prevalent different relationship between the structures.
Mice do not have distinguishable promoter regions and therefore no s and l alleles, so complete testing among these alleles is not really possible
The next best thing:
- WT mice (with two functioning SERT genes)
act as the representation of the l-allele
- HEZ [heterozygous] mice (with one
functioning and one KO SERT gene) act as
the s- allele
Part 1: Establish a standard for how s-allele humans react in the presence of stress as compared to l-allele patients
Part 2: How this aforementioned G x E interaction affects neuronal activity among previously implicated parts of the brain
Part 1: In the presence of stress, low expression of serotonin transporters within the brain by a promoter region causes greater susceptibility towards it impacts
Part 2: Neuronal firing within the brain is seriously affected by the amount of SERT expression is noted, especially in those areas most affected by stressful events (i.e. the amygdala, prefrontal cortex, and hippocampus)
- each consisting of 70 shocks per mouse
- each on average 15 seconds apart
- on average 3 seconds in duration
- Measure of current = 6 milliamps
- No where to escape
Mice were placed into Plexiglas activity chambers equipped with infrared beams to detect horizontal activity and vertical activity
Activity of mice was recorded for 30 min.
Inescapable shock reduced total locomotion of the mice
I.S. stress increased the proportion of total locomotion spent in the center region of the open field
Mice place into box w/ two compartments separated by a guillotine
At the beginning: subject experience slight shock
The amount of time it took the mouse to escape to the other chamber was measured.
Real story : expected and warranted results achieved
The I.S. HET mice took longer to escape to another chamber than did the I.S. HET
Expected significant different between the Controlled WT/HET and the stressed WT/HET
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