Evidence for independent osmosensitivity of lateral preoptic and lateral hypothalamic neurons

Tondat, Lynn Marie; Almli, C. Robert

doi:10.1016/0361-9230(76)90074-5

Cited by 18 publications

(1 citation statement)

References 28 publications

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“…The diffuse representation of osmoreceptor cells in the lateral preoptic area and the fact that rats with lesions restricted to the lateral preoptic show appropriate behavioral responses to dehydration raise questions about the functional significance of this area for the control of osmotic thirst (Coburn & Stricker, 1978). Also, deficits in thirst following large lesions of the lateral preoptic hypothalamus suggest not alterations of receptor mechanisms but, rather, second-order effects (Blass & Epstein, 1971;Malmo & Mundi, 1975;Tondat & Almli, 1976). In contrast, the functional significance of the area of the nucleus circularis is indicated by behavioral deficits following very small lesions and by intracellular changes following water deprivation (Harrell et al, 1978;Hatton, 1976;Tweedle & Hatton, 1976).…”

Section: Discussionmentioning

confidence: 99%

Nucleus circularis and lateral preoptic regulation of osmotic thirst

Wallace

Harrell

1983

Psychobiology

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Small bilateral lesions of the nucleus circularis in rats produced a deficit in osmotic thirst, whereas subjects with similar-sized lesions of the lateral preoptic hypothalamus were almost identical to sham-operated rats in response to an osmotic challenge. Therefore, osmosensitive cells probably are more concentrated in the area of the nucleus circularis than in the lateral preoptic area. However, moderate-sized lesions in the lateral preoptic area resulted in a deficit in osmotic thirst, particularly when the damage was posterior to the anterior commissure. This research suggested that osmosensitive cells are diffusely represented in the preoptic area but become more concentrated in the anterior hypothalamus. This conclusion raised questions about the functional importance of the preoptic for osmoregulation and pointed to a more critical role for the nucleus circularis. To explain the increased water retention and increased antidiuretic hormone release following injections of hypertonic saline into the blood supply of the diencephalon, Verney (1947) suggested that osmoreceptors existed in the vascular bed of supraoptic nucleus of the hypothalamus. These osmoreceptors were proposed by Verney to be located in the supraoptic and paraventricular nuclei, which both produced antidiuretic hormone. Later evidence suggested that hypothalamic osmoreceptors existed in the lateral preoptic, medial preoptic, anterior, and lateral nuclei (

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