Neuroreport
-
Case Reports
Disownership of left hand and objects related to it in a patient with right brain damage.
We describe a woman with right brain damage who denied the ownership of her left hand and of extracorporeal objects (e.g. rings) which were worn on the left hand itself. When the same objects were worn on the right hand or were held by the examiner, the patient correctly recognized them as her own. ⋯ Thus, by inference, the mental image of one's body may include inanimate objects which had been in contact or in close proximity with the body itself. These findings provide, for the first time, experimental support to the speculative notion of an extended body schema.
-
7-Chlorokynurenic acid (7-Cl-KYNA) and 5,7-dichlorokynurenic acid (5,7-Cl2-KYNA) are of therapeutic interest as potent glycine/N-methyl-D-aspartate NMDA) receptor antagonists, but are excluded from brain by the blood-brain barrier. We examined whether these compounds could be delivered to brain through their respective precursors, L-4-chlorokynurenine (4-Cl-KYN) and L-4,6-dichlorokynurenine (4,6-Cl2-KYN), which are amino acids. 4-Cl-KYN was shown to be rapidly shuttled into the brain by the large neutral amino acid transporter of the blood-brain barrier (K(m) = 105 +/- 14 microM, Vmax = 16.9 +/- 2.3 nmol min-1 g-1) and to be converted intracerebrally to 7-Cl-KYNA. 4,6-Cl2-KYN also expressed affinity for the transporter, but four-fold less than that of 4-Cl-KYN. In summary, the results show that because of their facilitated uptake 4-Cl-KYN and 4,6-Cl2KYN might be useful prodrugs for brain delivery of glycine-NMDA receptor antagonists.