Author/Editor | Ribarič, S; Stefanovska, A; Brzin, M; Kogovšek, M; Kroselj, P | |
Title | Biochemical, morphological, and functional changes during peripheral nerve regeneration | |
Type | članek | |
Source | Mol Chem Neuropathol | |
Vol. and No. | Letnik 15, št. 2 | |
Publication year | 1991 | |
Volume | str. 143-57 | |
Language | eng | |
Abstract | The success of axon regeneration after nerve injury should be judged by the extent to which the target organs regain their function. Recovery of muscle contraction involves axon regeneration, reestablishment of nerve-muscle connections, recovery of transmission, and muscle force. All these processes were investigated under the same experimental conditions and correlated in order to better understand their time-course and interdependence. The sciatic nerve of a rat was crushed in the thigh. The ingrowth of regenerating motor axons into the soleus (SOL) and extensor digitorum longus (EDL) muscles was monitored by measuring the activity of choline acetyltransferase (ChAT), a marker enzyme for cholinergic nerve terminals, in the muscles. The electron microscopic cytochemistry of acetylcholine esterase (AChE) was used to estimate the reestablishment of neuromuscular junctions in these two muscles. The recovery of muscle contraction was followed by measuring the force of isometric contraction in the triceps surae muscle in vivo. The pattern of ChAT recovery during reinnervation was similar in the EDL and SOL. The statistically significant increase of ChAT activity in these muscles, 14 d after the nerve crush, signified the entry of regenerating axons into the calf muscles. Electron microscopic cytochemistry revealed the first small nerve endings in contact with the denervated end plates 12 d after denervation. Subsequently, the number of reinnervated motor end plates and the surface area of the neuromusclar junctions steadily increased. The recovery of muscle force started between d 14 and 21 after the nerve crush. Thirty-five days after denervation, the difference between the muscle force of the reinnervated muscle and the control became statistically insignificant. Morphological normalization of the motor end plates was practically complete 33 d after denervation, concomitant with the normalization of the muscle force.(trunc.) | |
Descriptors | CHOLINE ACETYLTRANSFERASE MOTOR ENDPLATE MUSCLES NERVE REGENERATION PERIPHERAL NERVES SCIATIC NERVE MOTOR ENDPLATE MUSCLE CONTRACTION NERVE CRUSH PERIPHERAL NERVES RATS RATS, INBRED STRAINS TIME FACTORS |