Circadian rhythmicity in the nervous system of the cockroach, Periplaneta americana

Modification of Spontaneous Electrical Activity by Neural and Blood-Borne Factors in the Silkworm Bombyx mori L.

“…This shows that the spontaneous electrical activity could be modulated by blood-borne factors which may be of neural origin. The spontaneous electrical activity of the CNS is known to be influenced by neurohormones and neurohumors (Ozbas and Hodgson, 1958;Weiant, 1958;Milburn et al, 1960;Milburn and Roeder, 1962;Vijayalakshmi et al, 1977). Thus, in the present study it is possible that neural factors, humoral and/or hormonal, could be synthesized in the CNS and released at appropriate times to modulate the spontaneous electrical activity and consequently the overt behavioral activity of the silkworm with reference to feeding and spinning.…”

“…and releasing phases for neurohumoral and neurohormonal factors have been reported earlier in other invertebrates (Rao and Gopalakrishna Reddy, 1967;Vijayalakshmi et al, 1977;Rajarami Reddy et al, 1978). With regard to the neurohumoral factors, special emphasis has been laid on the neurotransmitters such as ACh.…”

Spontaneous Electrical Activity in the Nervous System and its Modification by Biogenic Amines in the Silkworm <i>Bombyx Mori </i>(L)

“…released by itself. Instances for such actions are available in literature on other invertebrates (Rao and Gopalakrishna Reddy, 1967;Vijayalakshmi et al, 1977;Rajarami Reddy et al, 1978). Further studies are required to consolidate the above assumptions.…”

“…However, this activity is generally reckoned as a reflection of the active state of the animal (Bullock and Horridge, 1965). With reference to circadian rhythms it has been demonstrated that the spontaneous electrical activity is higher during the periods of the day when the Indexed African Journals Online: www.ajol.info animal is active and lower during the periods of lower active state of the animal (Vijayalakshmi et al, 1977;Rajarami Reddy et al, 1978). The above observations lead to the assumption that the spontaneous activity could show alteration in its levels with the increase in overt activity of the silkworm as it proceeds from the 1st day to the 7th day of the 5th instar, leading towards the spinning activity.…”

“…Tyshtchenko and Mandelstam (1965) reported in oak silkworm that the highest level of spontaneous electrical activity with reference to both frequency and Indexed African Journals Online: www.ajol.info amplitude is present in the abdominal ganglia. Experiments on spontaneous electrical activity were performed on the abdominal cord in cockroach (Vijayalakshmi et al, 1977;Jacob Doss, 1993) owing to the higher activity which could be pharmacologically modified effectively. Further, the activity in the abdominal cord was found to be higher between the 2 nd and 3 rd abdominal ganglia.…”