The mammalian suprachiasmatic nucleus (SCN) controls the circadian rhythm of many physiological and behavioral events by an orchestrated output of the electrical activity of SCN neurons. We examined the propagation of output signals from the SCN into the hypothalamus, especially into the region of the paraventricular nucleus, through multimicroelectrode recordings using acute and organotypic brain slices. Circadian rhythms in spontaneous firing rate with a period close to 24 hr were demonstrated in the SCN, in directly adjacent hypothalamic regions, and in the region of the paraventricular nucleus of the hypothalamus, an important center for the integration of neuroendocrine, homeostatic, and autonomic functions. The activity rhythms recorded from structures outside of the SCN were in phase with the rhythms in the SCN. Cyclic information in the hypothalamus was lost after ablation of the SCN but could be restored by SCN grafts, indicating that a humoral factor is responsible for the restoration of circadian rhythmicity in the absence of neural connections. Periodic application of arginine–vasopressin (AVP) provided evidence that AVP can induce rhythmicity in the hypothalamus. These data indicate that the SCN uses a dual (neuronal and humoral) mechanism for communication with its targets in the brain.

Interest is growing in finding natural sources of effective antitumor agents that generate fewer side effects than conventional chemotherapeutic drugs. Avenanthramides (Avns) are such compounds; these phenolic molecules naturally occur in oats and have antioxidant, anti-inflammatory, and antiproliferative effects making them worthy of further research. The aim of this study is to characterise Avns’ curative ability and antineoplastic activity on solid-form Ehrlich tumors. For the study, 75 female mice were randomly and equally allocated to five groups (group 1-control, group 2-DMSO, group 3-positive control receiving Avns, group 4-mice with Ehrlich solid tumor, and group 5-Ehrlich solid tumor treated with Avns). Mice with Ehrlich solid tumors exhibit increased tumor volume; elevated expression of AFP, ALT, AST, Bcl2, CEA, cholesterol, creatinine, urea, MDA, PCNA, potassium, triglycerides, TNF-α, and NF-κB; and a concomitant decline in catalase, GSH, P53, and SOD. In the mice with Ehrlich tumors who received Avns, there appeared to be improvement in NF-κB TNF-α, tumor markers (AFP and CEA), electrolytes, liver and kidney function enzymes, and lipid profiles; reduced MDA level; improved antioxidant parameters; normalised liver protein, P53, and PCNA; and reduced Bcl2 expression. Pathological examination of tumor lesions also indicated improvement. These results suggest that Avns exhibit antineoplastic activity and possess antioxidant properties that enhance the antioxidant defence system, thus reducing the oxidative stress caused by Ehrlich solid tumors.