[Intrahypothalamic connections of the rostral and caudal portions of the hypothalamus (retrograde axonal horseradish peroxidase transport study)]. 
Unilateral injections of 0.2--0.3 mkl 30% horseradish peroxidase (HP) Sigma VI were performed to 4 groups of rats: into the medial and lateral preoptic areas, into the medial and lateral areas of the caudal hypothalamus.  After all injections performed the predominant amount of HP-positive neurons was found to situate ipsilaterally in the middle (tuberal) hypothalamic area, mainly in the frontal and lateral hypothalamic fields.  Owing to the data obtained, it is possible to conclude that the tuberal hypothalamic areas mentioned are the source of the afferent innervation within the hypothalamus for its rostral and caudal parts.