274
tritrodes (impedance 0.5–1.5 MΩ) were fabricated with three strands of insulated 20
μm-diameter 10 % platinum/iridium wire that terminated into a multipin underwater connector which joined to the telemetry tag. Two miniature capacitors, a differential amplifi er, low (400 Hz) and high (4 kHz) fi lters, and a circular inductive coil
were contained in the tag (Fig. 1a ). The neural signals were transmitted as a
frequency- modulated magnetic fi eld (90 kHz carrier, 20 kHz bandwidth), to the
receiver coils embedded in a recharging habitat and stage (RECHABS) (Fig. 1b ).
Fig. 1 ( a ) Photograph of the neural telemetry tag. ( A ) Electrode lead; ( B ) waterproof connector;
( C ) tag body with amplifi er, capacitors, and fi lters: ( D ) Inductive coil. ( b ) Dorsal view of the
experimental arena. The recharging habitat and stage ( RECHABS ) consists of the cylindrical habitat ( H ) and the octagonal stage ( S ). Neural telemetry and tag recharging could transpire when the
fi sh was in the habitat or over the stage. Fish movements were recorded with an overhead video
camera ( C ). Drawing is not to scale. Modifi ed from Palmer et al. ( 2005 )
A.F. Mensinger
tritrodes (impedance 0.5–1.5 MΩ) were fabricated with three strands of insulated 20
μm-diameter 10 % platinum/iridium wire that terminated into a multipin underwater connector which joined to the telemetry tag. Two miniature capacitors, a differential amplifi er, low (400 Hz) and high (4 kHz) fi lters, and a circular inductive coil
were contained in the tag (Fig. 1a ). The neural signals were transmitted as a
frequency- modulated magnetic fi eld (90 kHz carrier, 20 kHz bandwidth), to the
receiver coils embedded in a recharging habitat and stage (RECHABS) (Fig. 1b ).
Fig. 1 ( a ) Photograph of the neural telemetry tag. ( A ) Electrode lead; ( B ) waterproof connector;
( C ) tag body with amplifi er, capacitors, and fi lters: ( D ) Inductive coil. ( b ) Dorsal view of the
experimental arena. The recharging habitat and stage ( RECHABS ) consists of the cylindrical habitat ( H ) and the octagonal stage ( S ). Neural telemetry and tag recharging could transpire when the
fi sh was in the habitat or over the stage. Fish movements were recorded with an overhead video
camera ( C ). Drawing is not to scale. Modifi ed from Palmer et al. ( 2005 )
A.F. Mensinger