Limbic System (Lecture May 4, 2010)

Front 1

Papez circuit

Back 1

Mammillary bodies -->
(via mammillothalamic tract) -->
anterior nucleus of thalamus -->
cingulate gyrus -->
hippocampus -->
(via fornix) -->
Back to mammillary bodies

Front 2

Components of modern limbic system

Back 2

Papez circuit:
1. mammillary bodies
2.anterior thalamic nucleus
3. cingulate gyrus
4. hippocampus

and:
5. orbital & medial prefrontal cortex
6. ventral parts of Basal Ganglia (incl N. accumbens)
7. MDN of Thalamus
8. Amygdala

Front 3

** Subiculum

Back 3

**

Front 4

Hippocampal
Inputs/Outputs

Back 4

**

Front 5

Hippocampus Function

Back 5

- Critical for forming new declarative (episodic) memory

- NOT req'd to form new procedural memory, eg. "motor memory"
- Some lateralization of function. Assuming left hemisphere language dominance: L is more impt for verbal memory, and R for non-verbal memory
- Significant deficits usually require bilateral damage.

Front 6

Amygdala
Major divisions

Back 6

3 Major Divisions:
1. Basolateral Nuclei

2. Central Nucleus

3. Medial (Corticomedial) Nuclei

Front 7

Kluver-Bucy Syndrome

Back 7

**

Front 8

** Conditioned fear response

Back 8

- experiment where a sound is paired w/ foot shock

Front 9

Memory storage modulation by emotion

Back 9

- Recently formed memories may be influenced by emotional factors (mediated by hormones/NT) & drug interventions for a brief time after they are formed.

- These effects can strengthen or impair memories

- Effects blocked by lesions of the amygdala (in experimental models)

Front 10

Cingulate Gyrus

Back 10

**

Front 11

Orbital Frontal Cortex

Back 11

**