Emotion: Region Level: Amygdala
Amygdala and Sensory processing:
A sensory gateway to the emotions (Aggleton & Mishkin 1986).
Amygdala and Memory:
Fear Conditioning: (LeDoux 1991b)(Davis 1992)
(McGaugh et al 1990; McGaugh et al, 1991): Involvement of the amygdaloid
complex in neuromodulatory influences on memory storage.
Several neurochemical systems have been identified (Adapted from (McGaugh
1992)) and influence memory storage, in/by the amygdala:
Amygdala and Emotion:
Bilateral lesions of the amygdala produce tameness, abnormal exploratory
and sexual behaviors, and incapacity to learn aversive stimuli (Weiskrantz
Monkeys voluntarily work to obtain electrical brain stimulation of the
et al. 1980)
Emotion and the Amygdala: (LeDoux 1992).
The role of the amygdala in conditioned fear: (Davis, 1992) - The startle
The functional aspects of amygdala lesions in humans: A comparison with
findings from monkeys: (Aggleton, 1992).
Kindling and the Amygdala (Cain, 1992): Electrical stimulation of the amygdala.
Part of the LeDoux
Locate it on
a MRI Slice.
Locate it on
a Rat Brain Slice (sagital section).
An Exploded View of its nuclei (coronal section, adapted from (Aggleton,
- Lateral nucleus (AL) neurons receive sensory information from the thalamus
and cortex. It is a site of convergence of CS and US pathways in fear conditioning,
hence a possible site of synaptic modification underlying learning (Romanski
et al 1993).
Recent studies aim at elucidating the internal connectivity of the amygdaloid
complex, and understand the nature of its computation. The information
pathway seems to consist in a common entry point (the lateral nucleus),
several parallel streams to other nuclei (Medial, accessory basal, or basal,
for example) and a common output point (the central nucleus). Each of the
internal streams are modulated by other brain structures such as the hippocampus,
the frontal cortex or the hypothalamus.
(Pitkanen et al 1997).
Editor: Jean-Marc Fellous