FIGURE 4.

(A,B) Effects of a unilateral vestibular neurectomy on the density of [³H]N-α-methylhistamine binding sites in the vestibular nuclei and the prepositus hypoglossi. Changes in histamine H₃ receptor binding in the vestibular nuclei and the prepositus hypoglossi 1 (A) or 3 (B) weeks after unilateral vestibular neurectomy. Quantitative analysis is expressed as mean values and standard errors of femtomole of [³H]N-α-methylhistamine specifically bound per milligram of protein from autoradiograms. Data from the prepositus hypoglossi (PH), and the medial (MVN) and superior (SVN) vestibular nuclei are given as the average value of the right and left structures for the controls (black histograms); they are provided separately for each side [lesioned (thick hatched histograms) versus intact (thin hatched histograms)] for the cats killed 1 (A) or 3 (B) weeks after unilateral vestibular neurectomy. *P < 0.001, **P < 0.0001.