Attività mitotica e morfologia del midollo spinale durante lo sviluppo di un Teleosteo viviparo
During the growth of the spinal cord in a viviparous Teleost (Gambusia affinis) the mitotic ratio slowly decreases and falls after birth, but it rises in young fishes. Therefore mitoses are present till the end of the somatic growth. The mitotic activity is higher in the sensitive than in the motor region of the spinal cord: this is due to the slow differentiation of the alar plate. Starting from 3,5 mm embryos most of the mitoses are extraventricular owing to quick reduction of the central canal....