Deficits in bladder function are complications following spinal cord injury (SCI), severely affecting quality of life. Normal voiding function requires coordinated contraction of bladder and urethral sphincter muscles dependent upon intact lumbosacral reflex arcs and integration of descending and ascending spinal pathways. We previously reported, in electrophysiological recordings, that segmental reflex circuit neurons in anesthetized male rats were modulated by a bilateral spino-bulbo-spinal pathway in the mid-thoracic lateral funiculus. In the present study, behavioral measures of bladder voiding reflexes and hematuria (hemorrhagic cystitis) were obtained to assess the correlation of plasticity-dependent recovery to the degree of lateral funiculus sparing and mid-thoracic lesion level. Adult rats received mid-thoracic-level lesions at one of the following severities: complete spinal transection; bilateral dorsal column lesion; unilateral hemisection; bilateral dorsal hemisection; a bilateral lesion of the lateral funiculi and dorsal columns; or a severe contusion. Voiding function and hematuria were evaluated by determining whether the bladder was areflexic (requiring manual expression, i.e., ''crede maneuver''), reflexive (voiding initiated by perineal stroking), or ''automatic'' (spontaneous voiding without caretaker assistance). Rats with one or both lateral funiculi spared (i.e., bilateral dorsal column lesion or unilateral hemisection) recovered significantly faster than animals with bilateral lateral funiculus lesions, severe contusion, or complete transection. Bladder reflex recovery time was significantly slower the closer a transection lesion was to T10, suggesting that proximity to the segmental sensory and sympathetic innervation of the upper urinary tract (kidney, ureter) should be avoided in the choice of lesion level for SCI studies of micturition pathways. In addition, hematuria duration was significantly longer in males, compared to females, despite similar bladder reflex onset times. We conclude that the sparing of the mid-thoracic lateral funiculus on one side is required for early recovery of bladder reflex voiding function and resolution of hematuria.
Four groups of 70-wk-old broiler breeder females were fed once daily at 0600, 1000, 1400, and 1800 h to determine the effect of feeding time and eating on body temperature. The photoperiod was from 0430 to 1930 h. Four floor pens of 30 hens each were assigned per feeding time. Following a 9-day adjustment period, body temperature was determined, in series, by rectal probe of 5 birds/pen at 7 and 3 h prefeeding and 1, 5, 9, and 13 h postfeeding. Body temperature was increased .5 C at 1 h postfeeding in all groups and at 5 h postfeeding in the 0600-h fed group. The rate of feed consumption was fastest with afternoon feeding. Four 1-yr-old broiler breeder males were implanted with an FM radio transmitter for monitoring body temperature and housed in an environmental control chamber. Body temperature was monitored when the birds were fed at 0600, 1000, 1400, and 1800 h. The chamber temperature cycled from 22.2 to 33.3 C (22.2 C: 2200 to 0800 h; 33.3 C: 1200 to 1600 h; 27.8 C: 0800 to 1200 h and 1600 to 2200 h). Lights were on from 0430 to 1930 h. Body temperature changes were also monitored under constant temperature (27.8 C) and light for birds fed ad libitum or at 1000 h. Body temperature increased as much as 1.5 C following feeding and reached a maximum at 5, 4, 3, and 2 h postfeeding at feeding times of 0600, 1000, 1400, and 1800 h, respectively. Males unable to feed displayed a significantly increased body temperature when they observed other birds eating. A specific body temperature response to feeding activity was observed only when males were fed once daily under constant environment.
Complications of spinal cord injury in males include losing brainstem control of pudendal nerve-innervated perineal muscles involved in erection and ejaculation. We previously described, in adult male rats, a bulbospinal pathway originating in a discrete area within the medullary gigantocellularis (GiA/Gi), and lateral paragigantocellularis (LPGi) nuclei, which when electrically microstimulated unilaterally, produces a bilateral inhibition of pudendal motoneuron reflex circuitry after crossing to the contralateral spinal cord below T8. Microstimulation following a long-term lateral hemisection, however, revealed reflex inhibition from both sides of the medulla, suggesting the development or unmasking of an injury-induced bulbospinal pathway crossing the midline cranial to the spinal lesion. In the present study, we investigated this pathway anatomically using the transsynaptic neuronal tracer pseudorabies virus (PRV) injected unilaterally into the bulbospongiosus muscle in uninjured controls, and ipsilateral to a chronic (1-2 months) unilateral lesion of the lateral funiculus. At 4.75 days post-injection, PRV-labeled cells were found bilaterally in the GiA/Gi/LPGi with equal side-to-side labeling in uninjured controls, and with significantly greater labeling contralateral to the lesion/injection in lesioned animals. The finding of PRV-labeled neurons on both sides of the medulla after removing the mid-thoracic spinal pathway on one side provides anatomical evidence for the bilaterality in both the brainstem origin and the lumbosacral pudendal circuit termination of the spared lateral funicular bulbospinal pathway. This also suggests that this bilaterality may contribute to the quick functional recovery of bladder and sexual functions observed in animals and humans with lateral hemisection injury.
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