The amygdala is a nuclear complex related to emotional behaviour and stress, which lie in the dorsomedial temporal pole, anterior to the hippocampus, and close to the tail of the caudate nucleus.

The septum is a midline and paramedian structure. Its upper portion corresponds largely to the bilateral laminae of fibres, sparse grey matter and neuroglia, known as the septum pellucidum, which separates the lateral ventricles.

Both medial amygdala and lateral septum have been implicated in social recognition and anxiety-related behaviour. At a molecular level, a deficiency in the vasopressin receptor V1aR in mice has important consequences for these behaviours.

Bielsky et al., found that V1aR antagonists in wild-type mice led to social impairments when targeted to the lateral septum but not the medial amygdala (The V1a vasopressin receptor is necessary and sufficient for normal social recognition: a gene replacement study. Neuron 47, 503-513, 2005.). Moreover, re-expressing V1aR in the lateral septum of mice deficient in V1aR led to complete rescue of social recognition behaviours, confirming a crucial role for this region in such a complex behaviour.


BM&L-October 2005