scholarly journals ELECTRICAL ACTIVITY OBSERVED IN VITRO IN THIN SECTIONS FROM GUINEA-PIG CEREBELLUM

1974 ◽  
Vol 24 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Chosaburo YAMAMOTO
Keyword(s):  
Guinea Pig ◽  
Electrical Activity ◽  
Thin Sections

scholarly journals Effects of vasopressin on electrical activity in the guinea-pig supraoptic nucleus in vitro.

1983 ◽  
Vol 33 ◽  
pp. 151
Author(s):  
Nobukuni Ogata ◽  
Hidehiko Abe ◽  
Tadashi Matsuo ◽  
Masumi Inoue
Keyword(s):  
Guinea Pig ◽  
Electrical Activity ◽  
Supraoptic Nucleus

scholarly journals ACROSOMAL DISRUPTION IN SPERM

1974 ◽  
Vol 63 (2) ◽  
pp. 466-479 ◽  
Author(s):  
Daniel S. Friend ◽  
Irene Rudolf
Keyword(s):  
Plasma Membrane ◽  
Guinea Pig ◽  
Plasma Membranes ◽  
Freeze Fracture ◽  
Direct Consequence ◽  
Thin Sections ◽  
Geometric Patterns ◽  
Acrosomal Membrane ◽  
Principal Piece

"Capacitation" is a physiological event which alters sperm to permit rapid penetration through oocyte investments and fusion between gametes. Acrosomal "reaction," the physiological release of acrosomal contents, occurs after this facilitating process. In this study, acrosomal "disruption" of guinea pig and rat sperm was achieved in vitro by incubating sperm together with the follicular contents of superovulated mice. The samples contained both "reacted" and "disrupted" sperm. Thin sections of affected sperm revealed rupture and vesiculation of the plasma membrane overlying the acrosome, as well as loss of both the outer acrosomal membrane and the acrosomal content. Freeze-fracture revealed disintegration of the characteristic geometric patterns in regions of the acrosomal and plasma membranes thus disrupted and major modifications in particle distribution in the sperm tail. In the guinea pig, strands of 6–8-nm particles, usually confined to the plasma membrane of the midpiece, which overlies mitochondria, also appeared in the principal piece. Likewise, in rat sperm, bands of similarly small particles formed acute angles throughout the membrane of the principal piece. Compared with the membranes of control preparations, these membrane alterations are apparently a direct consequence of incubation with ovarian follicular contents.

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