Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Dopamine regulation of testicular activity in intact and hypophysectomized frogs,Rana esculenta (1993)
    Springer
    Cellular and molecular life sciences 49 (1993), S. 65-67 
    Details
    ISSN: 1420-9071
    Keywords: Testis ; spermiation ; L-dopa ; pimozide ; Amphibia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In intact frogs, both GnRHA and L-dopa were able to increase testicular and plasma androgen levels and to induce spermiation. The dopamine antagonist pimozide inhibited both the effects of L-dopa but not those of GnRHa. Hypophysectomy reduced androgen levels, but spermiation was still induced by both GnRHa and L-dopa, suggesting that these agents can directly influence the testis through a route not involving the pars distalis. Again, pimozide antagonised spermiation induced by L-dopa but not that induced by GnRHa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01928792
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A gonadotropin releasing hormone analog induces spermiation in intact and hypophysectomized frogs,Rana esculenta (1989)
    Springer
    Cellular and molecular life sciences 45 (1989), S. 1118-1121 
    Details
    ISSN: 1420-9071
    Keywords: Testis ; spermiation ; gonadotropins ; GnRH agonist ; GnRH antagonist ; Amphibia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sperm-releasing activity of a gonadotropin releasing hormone (GnRH) agonist, Buserelin (GnRH*) and hypophysis homogenate (PD) preparations was studied in intact and hypophysectomized (PDX) frogs,Rana esculenta. In addition, human chorion gonadotropin (hCG) was tested in PDX animals, and GnRH antagonist (GnRHA) treatments were carried out in intact and PDX animals, in combination with the hormonal injections. GnRH* or PD treatments were able to elicit spermiation in intact and PDX animals. While GnRH*, injected 24 h later, was again effective in inducing spermiation in intact animals, this was not the case in PDX frogs. GnRHA counteracted GnRH* effects in intact frogs. Moreover, in PDX animals GnRHA injections counteracted the spermreleasing activity induced by hCG or GnRH*, but failed to inhibit sperm-releasing activity induced by PD homogenate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01950175
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A look into the cock-pit of the fly (1976)
    Springer
    Cell & tissue research 171 (1976), S. 101-122 
    Details
    ISSN: 1432-0878
    Keywords: Optic ganglia-lobular plate ; Fly ; Musca domestica ; Microarchitecture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An anatomical investigation has been carried out on the third optic ganglion of the fly, Musca domestica. Two systems of giant units, the dendritic arborizations of which are arranged orthogonally relative to each other, dominate the neuropile of this ganglion. The elements of the two systems have been reconstructed using a graphical procedure based on histological sections. One system branches predominantly in the dorsoventral direction, the other one in the anterior-posterior direction. Both systems of the giant units have a twin system composed of elements smaller in diameter and strictly parallel to the main units. The two systems have been termed the Vertical and Horizontal Systems. The elements of the two systems of fibers project into the periesophageal region where they come into contact with other descending elements. Electron microscopic investigations show that the two systems are post-synaptic at the level of the ganglion from which they originate. The horizontal system has been shown to be post and pre-synaptic in nature during its course in the mid-brain and ultimately presynaptic at its endings in the periesophageal ring. The peculiar geometric arrangement of the two anatomical systems of fibers suggests a precise function in relation to the visual world and in particular to the detection of the direction of motion. The accuracy of the structural pattern displayed by the giant units in the lobular plate seems to suggest that this optic ganglion represents the ultimate orderly projection of the external world in the brain of the fly. A short review of the electrophysiological data concerning this ganglion has been tentatively correlated with some behavioral data related to the visual orientation and fixation in insects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219703
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...