The intravenous administration of procaine shows relatively specific activation of limbic structures. Several investigators have utilized this property of procaine to probe limbic system dysfunction in neuropsychiatric disorders. The dose of procaine utilized in human studies varies significantly, however, and the optimal dose of procaine as a limbic probe has not been demonstrated. In two 10-individual groups of healthy female volunteers, we assessed the regional cerebral blood flow (rCBF) response, by single-photon emission computed tomography (SPECT), to saline and 1.38 mg/kg procaine (Group I), and saline, 0.5 mg/kg and 1.0 mg/kg procaine (Group II). Compared to saline, 0.5 mg/kg procaine produced minimal rCBF changes, 1.0 mg/kg procaine induced both limbic and non-limbic activation, and 1.38 mg/kg procaine showed relatively specific rCBF limbic activation. Subjective responses increased in a dose-response manner. We conclude that a dose of 1.38 mg/kg procaine provides a more limited and specific activation of limbic structures than 1.00 mg/kg procaine and thus may be more useful as a specific probe of limbic function.
- Cocaine-related disorders
- Limbic system
- Single-photon emission computed tomography
ASJC Scopus subject areas
- Psychiatry and Mental health
- Radiology Nuclear Medicine and imaging
- Biological Psychiatry