Record Details

Flanigan, Jr, W F
Sleep and wakefulness in iguanid lizards, Ctenosaura pectinata and Iguana iguana
Brain Behavior and Evolution
1973
Journal Article
8
6
401-436
Iguana iguana;Ctenosaura pectinata
Black (Ctenosaura pectinata) and green (Iguana iguana) iguanid lizards were implanted with chronic electrodes in forebrain, orbital cavities and nuchal muscles; electrodes were also attached to abdominal cavity skin. Electrographic recordings were obtained for 7–11 consecutive days. Behavioral response latencies during behavioral wakefulness and behavioral sleep were evaluated. Four characteristic postures described the behavior of lizards: (1) limbs flexed and supporting body, head and neck elevated, eyes open (active waking); (2) posture similar to above, but with body resting on floor (quiet waking); (3) limbs slightly flexed or one to three limbs extended backward and positioned against body/tail, head rested on floor, eyes usually closed, and (4) all limbs extended backward and positioned against body/tail, head on floor, eyes usually closed. Frequency and latency of response to stimulation, respectively, changed from 94.1–100% and 0.62–0.69 sec for behavioral waking to 50–51.3% and 1.32–2.01 sec for Postures 3 and 4 (eyes closed). Postures 3 and 4 (eyes closed) denote behavioral sleep, i.e., stereotypic posture, immobility, increased response threshold, and rapid state reversibility. EEGs were dominated by small amplitude monophasic sharp and sawtooth waves during behavioral waking, but EEGs became polymorphic and irregular in form during behavioral sleep (EEG frequencies slightly declined and amplitudes substantially diminished with sleep). Neither epochs of slow waves nor paradoxical sleep were recorded. Arhythmic (up to 385 µV) spikes (25–80 msec duration) and sharp waves (80–190 msec duration) characterized lizard EEGs. Spike and sharp wave activity reached peak levels only during behavioral sleep and vanished or dramatically declined with waking. Spikes and sharp waves substantially increased during recovery from 48 h of enforced waking.