Gaze-Related Response Properties of DLPN and NRTP Neurons in the Rhesus Macaque

Abstract

Ono, Seiji, Vallabh E. Das, and Michael J. Mustari. Gaze-related response properties of DLPN and NRTP neurons in the rhesus macaque. J Neurophysiol 91: 2484 -2500, 2004. First published January 28, 2004 10.1152/jn.01005.2003. The dorsolateral pontine nucleus (DLPN) and nucleus reticularis tegmenti pontis (NRTP) are basilar pontine nuclei important for control of eye movements. The aim of this study was to compare the response properties of neurons in DLPN and rostral NRTP (rNRTP) during visual, oculomotor, and vestibular testing. We tested 51 DLPN neurons that were modulated during smooth pursuit (23/51) or during motion of a large-field visual stimulus (28/51). Following vestibular testing, we found that the majority of smooth pursuit-related neurons in DLPN were best classified as gaze (13/23) or eye velocity (7/23) related. Only a small percentage (3/51) of DLPN neurons responded during vestibular ocular reflex in the dark (VORd). We tested rNRTP neurons as described above and found the majority of neurons (35/43) were modulated during smooth pursuit or during motion of a large-field stimulus only (4/43). A significant proportion of our rNRTP gaze velocity neurons (10/18) were also modulated during VORd. We found that the majority of smooth pursuit related neurons in rNRTP were best classified as gaze velocity (18/35) or gaze acceleration (11/35) sensitive. The remaining neurons were classified as eye position or eye/head related. We used multiple linear-regression modeling to determine the relative contributions of eye, head and visual inputs to the responses of DLPN and rNRTP neurons. Our results support the suggestion that both DLPN and rNRTP play significant roles not only in control of smooth pursuit but also in control of gaze.

Latency of vestibular responses of pursuit neurons in the caudal frontal eye fields to whole body rotation

“…The caudal FEF also contains many gaze-velocity neurons (Fukushima et al 2000, also in this study). Gaze-velocity signals are also found in the dorsal vermis (Shinmei et al 2002), the dorsolateral and dorsomedial pontine nuclei, and the nucleus reticularis tegmenti pontis (NRTP, Ono et al 2004). Because the FEF sends projections to these pontine areas, it could send gaze-velocity signals to the floccular region and dorsal vermis through these pontine nuclei and NRTP (Ono et al 2004).…”

“…Gaze-velocity signals are also found in the dorsal vermis (Shinmei et al 2002), the dorsolateral and dorsomedial pontine nuclei, and the nucleus reticularis tegmenti pontis (NRTP, Ono et al 2004). Because the FEF sends projections to these pontine areas, it could send gaze-velocity signals to the floccular region and dorsal vermis through these pontine nuclei and NRTP (Ono et al 2004). Chemical inactivation of the caudal FEF impairs not only smooth pursuit but also VOR cancellation (Fukushima et al 1999a).…”

“…Not only gaze-velocity signals but also eye/head-velocity signals are represented in the caudal FEF, pontine nuclei, NRTP (Ono et al 2004), the cerebellar floccular region, and dorsal vermis (Lisberger and Fuchs 1978;Miles et al 1980;Sato and Noda 1992;Fukushima et al 1999b;Belton and McCrea 2000;Shinmei et al 2002). Gaze-velocity signals alone would be insufficient for adequate control of smooth eye movements to a stationary spot in space during whole body rotation (i.e., VOR x1), because virtually no gaze movement would be required in such a situation and gaze velocity neurons become less active (e.g., Lisberger and Fuchs 1978).…”

Neural dynamics of saccadic and smooth pursuit eye movement coordination during visual tracking of unpredictably moving targets

“…The output from these cells is integrated by the model NRTP's velocity neurons What anatomical substrates realize these mechanisms? In particular, NRTP contains gaze acceleration and gaze velocity cells (Ono et al, 2005;Ono et al, 2004;Suzuki et al, 1999;Suzuki, Yamada, & Yee, 2003;T. Yamada et al, 1996) that act as velocity-comparison and velocity integrator cells (Figure 4).…”

“…) LIP to SC, SC to LIP Saccadic target priming information (Lynch, Graybiel, & Lobeck, 1985) FEF to PPRF Motor Command for saccade generation (Huerta et al, 1987;Leichnetz, Smith, & Spencer, 1984 (Tusa & Ungerleider, 1988) MST to DLPN Target and background speed and direction input is projected (Glickstein et al, 1980;Mustari et al, 1988;Ono et al, 2004;Suzuki & Keller, 1984) MST to FPA Direction and speed sensitive of target data (Churchland & Lisberger, 2005;Maioli et al, 1992;Tian & Lynch, 1997; J. R. Tian & Lynch, 1996aTusa & Ungerleider, 1988) FPA to rNRTP Direction sensitive target input reach eye acceleration cells in rNRTP. (Suzuki et al, 1999;Suzuki et al, 2003;T.…”