Cellular structure, brain

MRI can provide valuable information on the progression of vasogenic edema and necrosis in the living organism. Free and bound water (e.g., water in the ventricles vs. water bound to cellular structures) can be discriminated based on different T1 and T2 relaxation times (Bakay et al. 1975 Naruse et al. 1982). Typical T1 and T2 relaxation times of normal rat brain at 4.7 T are 869+145 ms and 72+2 ms (caudate putamen) and 928 117 ms and 73 2 ms (cortex), while more liquid structures such as edematous tissue, cysts or CSF will lead to significantly elevated T1 and T2 relaxation times (Hoehn-Berlage et al. 1995). 

Although the hypothalamus is considered the source of peptide hormones which influence the pituitary and and other target tissues outside the brain, the specific cells which produce these hormones have yet to be isolated. Because of the extreme complexity of its cellular structure compared with other endocrine organs, the precise site of production of many of the hypothalamic hormones... 

---