Study type: Technical/dosimetric study (experimental study)

Changes in serotonin in rat brain during slow-wave sleep and paradoxical sleep: application of the microwave fixation method to sleep research. tech./dosim.

Published in: Brain Res 1980; 189 (2): 570-575

Aim of study (acc. to editor)

To study changes in serotonin (5-HT) and its metabolite 5-hydroxyindole acetic acid (5-HIAA) in rat brain during slow-wave sleep and paradoxical sleep.

Background/further details

The microwave fixation method was applied. Rats were sacrified by microwave irradiation of the head (2450 MHz, 5 kW, 2.0 sec) after 10 min of slow-wave sleep or wakefulness or paradoxical sleep.



Exposure Parameters
Exposure 1: 2.45 GHz
Exposure duration: 2 s

Exposure 1

Main characteristics
Frequency 2.45 GHz
Exposure duration 2 s
Exposure setup
Measurand Value Type Method Mass Remarks
power 5 kW - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Since the polygraphic records did not change just before exposure and the brains were fixed within 2 sec., the authors concluded that their procedure seems to be better for fixation of the brain at various states of sleep and wakefulness than previous methods (such as KCl injection or brain biopsy). Serotonin content was higher in the cerebral cortex and midbrain during both phases of sleep than during wakefulness.The 5-HIAA content in the hippocampus was higher during slow-wave sleep than during wakefulness. Similar tendencies were revealed in other regions, but not statistically significant. The 5-HIAA content to the cerebral cortex, hippocampus, midbrain and pons and medulla oblongata were lower during paradoxical sleep than during slow-wave sleep.

Study character:

Study funded by