Altered operant behavior of adult rats after perinatal exposure to a 60-Hz electromagnetic field.
Rats were sham exposed or exposed perinatally to a 60-Hz electromagnetic field, 22 days in utero and the first 8 days post partum. Each of the 30 once-daily exposures was 20 h in duration. The electric component of the field was vertical 30 kV/m rms, and the magnetic field component was 100 microTG rms. Later, as adults, male rats were trained to emit an operant response when reinforced with food on a multiple, random-interval schedule. Exposed rats (N = 21) gradually came to respond at significantly lower rates than did sham-exposed controls (N = 20). This finding was confirmed and extended in a second, independently performed experiment. After a sequence including operant conditioning followed by experimental extinction of responding and then by a suspension of conditioning and finally by more than a month of reconditioning, slower rates of responding were found to persist in the adult animals. The evidence of altered behavior several months after combined, fetal-neonatal exposure to an electromagnetic field presents an interesting contrast with other findings: Field-exposed rats did not differ from sham-exposed rats in terms of body mass, physical appearance, grossly observed activity level, or incidence of disease.
Salzinger
K
K
Polytechnic University, Brooklyn, New York 11201.
Freimark
S
S
McCullough
M
M
Phillips
D
D
Birenbaum
L
L
D000818:Animals; D000831:Animals, Newborn / Q000293:injuries*; D003216:Conditioning, Operant / Q000502:physiology*; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats