we have measured levels of beta-lipotropin , beta-endorphin , and n-acetyl-beta-endorphin in the plasma , cerebrospinal fluid ( csf ) , and caudal medullary brain containing the respiratory-related portion of the nucleus tractus solitarius ( nts ) of 2.5 +/- 1.0- ( sd ) and 38.2 +/- 3.7-day-old naive uninstrumented piglets .
C0006104
brain
C0175518
the