ABSTRACT
This study was aimed to evaluate the effects of dietary n-6:n-3 ratio and Vitamin E on the membrane properties and motility characteristics of spermatozoa in boars. Forty Duroc boars were randomly distributed in a 2 × 2 factorial design with two n-6:n-3 ratios (14.4 and 6.6) and two Vitamin E levels (200 and 400 mg kg-1). During 16 weeks of treatment, fresh semen was collected at weeks 0, 8, 12, and 16 for measurements of motility characteristics, contents of fatty acids, membrane properties (membrane fluidity and membrane integrity), and lipid peroxidation of the spermatozoa. The semen was diluted in Beltsville Thawing Solution (BTS) extender and stored at 17°C, and the sperm motility was assessed at 12, 36, 72, and 120 h of storage. The 6.6 n-6:n-3 dietary ratio increased the contents of n-3 polyunsaturated fatty acids (PUFAs) and docosahexaenoic acid (DHA) and improved the membrane integrity and membrane fluidity of the spermatozoa, resulting in notably increased total motility, sperm progressive motility, and velocity parameters of fresh semen. Feeding diet with Vitamin E (400 mg kg-1) prevented sperm lipid peroxidation, and resulted in higher total motility and sperm progressive motility in fresh and liquid stored semen. In conclusion, the adjustment of n-6:n-3 ratio (6.6) and supply of Vitamin E (400 mg kg-1) successfully improved sperm motility characteristics and thus may be beneficial to the fertility of boars, which might be due to the modification of the physical and functional properties of spermatozoa membrane in response to dietary supplementation.
ABSTRACT
Objective To study the membrane properties of rat retinal ganglion cells during postnatal development, including the passive membrane properties and the action potentials evoked by depolarizing current injections and the relationship between the membrane properties and ages. Methods Whole cell patch clamp recordings of the retinal ganglion cells (RGCs) in retinal slices of postnatal rats (age ranging from postnatal days 7 to 30) were performed. Results (1) A total of 112 RGCs were recorded from postnatal rats. (2) The electrophysiological properties of RGCs changed significantly during development. The excitability of RGCs increased in an age-dependent manner. There was significant difference between before-eye-opening group(P7-13d) and after-eye-opening group(P14-30d) . (3) Three different discharge patterns of RGCs in response to sustained depolarizing current pulses were recorded: single-spike firing, transient firing and sustained firing. During development, retinal ganglion cells of rats exhibited pronounced changes in the discharge patterns(P