The Amygdala

By: Alinka, Harel, Vjosa

General Information; Function

General Information; Location

Study 1• Aim: Determine the volume in the amygdala in a series of brains

post-mortems• Procedure:

– Amygdala volume was estimated using point-counting in both hemispheres of brains of 10 male and 8 female patients with schizophrenia

– Had a comparison group of 9 male and 9 female post-mortems without neuropsychiatric disorder

• Results: No significant reduction of amygdala found

• Implications: Significant volume reduction isn’t not consistent feature in schizophrenia

Study 2

• Aim: Examine neural activity in amygdala during episodes of mania. • Procedure:

– 9 manic participants & 9 healthy comparison subjects underwent fMRI while performing a neuropsychological paradigm known to activate the amygdala

– Experimental Task: participants see faces displaying affection– Control task: geometric forms– Goal: Match them to one of two similar images presented at same time

• Results: Manic participants had significantly increased activation in the left amygdala and reduced bilateral activation in the lateral orbit frontal cortex relative to the comparison participants.

• Implications: Increased activation in the amygdala and decreased activation in the orbitofrontal cortex may represent disruption of a specific neuroanatomic circuit involved in mania. These brain regions may be implicated in disorders involving regulation of affect.

Study 3• Aim: Investigate what happens in the brain during and after phobia

treatment• Procedure:

– Examined brain activity of 18 people w/ social phobia as they spoke in front of a group using PET scans

– 1/3 of the participants received 9 weeks of cognitive-behavioral therapy– 1/3 received the selective serotonin reuptake inhibitor Citalopram and 1/3

received no treatment. – Participants were tested again, using the same public speaking task, at 9

weeks and again after one year.

• Results: Activation in the amygdala and related cortical areas at 9 weeks could predict which people's symptoms would improve after one year

Dysfunction