Shi-Ming He | PubMed Health

PubMed2006

TNF-alpha involves in altered prefrontal synaptic transmission in mice with persistent inflammatory pain.

Tumor necrosis factor alpha (TNF-alpha) is implicated in the development of persistent pain. Its expression increases both spinally and supraspinally after peripheral inflammation. The anterior cingulate cortex (ACC) is a forebrain structure known for its roles in pain transmission and modulation. Prefrontal synaptic transmission is potentiated in mice with chronic pain through an enhancement of presynaptic transmitter release. However, it is not known if TNF-alpha expression is altered in the ACC in response to persistent pain and if synaptic transmission within this region is modulated by TNF-alpha. In the present study, we examined TNF-alpha expression in the mouse ACC following hind-paw administration of complete Freund's adjuvant (CFA) and examined the role of TNF-alpha in ACC synaptic transmission. Quantification of TNF-alpha at the protein level (by ELISA) revealed enhanced expression following CFA-induced peripheral inflammation. In vitro whole-cell patch-clamp recordings revealed that TNF-alpha significantly enhanced synaptic transmission through increased probability of neurotransmitter release in the ACC. Our findings provide evidence that presynaptic alterations caused by peripheral inflammation is partly attributable to the up-regulation of TNF-alpha in the ACC.

Animals↗

PubMed2005

Induction of estrus in suckled female yaks (Bos grunniens) and synchronization of ovulation in the non-sucklers for timed artificial insemination using progesterone treatments and Co-Synch regimens.

The objectives of the present study were to evaluate the induction of estrus and fertility in yak cows treated with Co-Synch regimens or progesterone (P(4)). In Experiment 1, postpartum suckled yaks were assigned to three treatments: (1) A (n=28), insertion of an intravaginal device containing P(4) (CIDR) on Day 0, PGF(2alpha) (i.m.) on Day 6 and PMSG (i.m.) at the time of CIDR removal on Day 7 (P(4)-PGF(2alpha)-PMSG); (2) B (n=21), PGF(2alpha) (i.m.) on Day 6 and PMSG on Day 7; (3) C (n=26), control group. Seven yak bulls were grazed with the cows for natural breeding. Rate of estrus within 96h of the end of treatment was greater (P<0.05) in A (100.0%) than in B (28.6%) or C (0.0%). First service conception rate (CR) determined by serum P(4) on Day 21 after breeding was greater (P<0.05) in A (78.6%) than in B (22.2%). Also, pregnancy rate (PR) during the breeding season was greater (P<0.05) in A (82.1%) than in B (19.0%) and C (7.7%). In Experiment 2, non-suckled yaks that calved in previous years but not in the current year were assigned to three treatments: (1) A (n=31), GnRH (i.m.) on Day 0, followed by PGF(2alpha) on Day 7 and timed artificial insemination (TAI) concurrently with GnRH treatment on Day 9 (Co-Synch regimen); (2) B (n=50), a CIDR device for 7 days plus PGF(2alpha) and PMSG at the time of CIDR withdrawal on Day 7 and TAI on Day 9 (P(4)-PGF(2alpha)-PMSG); (3) C (n=50), yak cows were artificially inseminated at spontaneous estrus. Frozen semen of Holstein and Jersey were used for insemination in Experiment 2. The CR assessed by rectal palpation 35 days after TAI was not different in A (22.6%), B (30.0%) and C (33.3%), but PR was greater in A and B than in C, when based on those cows presented for estrous synchronization programs. It is concluded that P(4)-PGF(2alpha)-PMSG protocol could efficiently induce estrus and result in an acceptable pregnancy rate in postpartum suckled yak cows. This technique and Co-Synch regimen can be applied successfully for TAI of non-suckled yak cows.

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