been identified in the budgerygah neurohypophysis (see Table 4.1) , and water deprivation for 7 days has no effect on the associated stainable neurosecretory material
present (UEMURA, 1964). More severe deh ydrating procedures deplete the neurosecretory products in the zebra finch (OKSCHE et al., 1963). It seems likely that the
low water content of th e excreta which is observed when these birds are deprived
of drinking water reflects, at least partly, a renal action of vasotocin in limiting
the formation of urine. The failure of water deprivat ion to deplete neurosecretory
material in the neural lobe of the budgerygah is reminiscent of observations in desert
rats, which were discussed earlier, and may reflect a high rate of hormone synthesis.
Information about neurohypophysial function that would be interesting and relatively easy to obtain includes the effects of vasotocin on urine flow in these birds
as well as determinations of the storage levels of this peptide in the neural lobe.
The regulation of salt metabolism in the budgerygah and zebra finch has not
been investigated. These birds live in areas where the sodium content of the plants
is often low, while seeds , which they normally feed on, also have a low sodium
level. The role of the adrenocortical hormones in such processes is potentially important but no information is available about this either.
134
present (UEMURA, 1964). More severe deh ydrating procedures deplete the neurosecretory products in the zebra finch (OKSCHE et al., 1963). It seems likely that the
low water content of th e excreta which is observed when these birds are deprived
of drinking water reflects, at least partly, a renal action of vasotocin in limiting
the formation of urine. The failure of water deprivat ion to deplete neurosecretory
material in the neural lobe of the budgerygah is reminiscent of observations in desert
rats, which were discussed earlier, and may reflect a high rate of hormone synthesis.
Information about neurohypophysial function that would be interesting and relatively easy to obtain includes the effects of vasotocin on urine flow in these birds
as well as determinations of the storage levels of this peptide in the neural lobe.
The regulation of salt metabolism in the budgerygah and zebra finch has not
been investigated. These birds live in areas where the sodium content of the plants
is often low, while seeds , which they normally feed on, also have a low sodium
level. The role of the adrenocortical hormones in such processes is potentially important but no information is available about this either.
134