Responses to tones of single cells in nucleus magnocellularis and nucleus angularis of the redwing blackbird (Agelaius phoeniceus)

Heterogeneous Calretinin Expression in the Avian Cochlear Nucleus Angularis

“…In vitro physiological response types have been defined in the chick and include several varieties of repetitive-spiking cell types and a phasic, "single spiking" response types, the latter of which resembled neurons in the timing pathways Fukui and Ohmori 2003;Kuo et al 2009;Soares et al 2002); these intrinsic properties may have important implications for both level and spectrotemporal processing in NA (Kreeger et al 2012). Physiological responses types in vivo corresponded closely to those found in the mammal ventral cochlear nucleus, including "primarylike" (resembling phasic-tonic nerve discharges), "chopper" (characterized by intrinsic repetitive spiking and poor phase-locking to the carrier wave), and "onset" types (Hotta 1971; Köppl and Carr 2003;Sachs and Sinnott 1978;Warchol and Dallos 1990; see also Köppl and Carr (2003) for a discussion of these response types in the avian system). Together, these data indicate that NA likely supports multiple, parallel streams of acoustic processing besides level coding for binaural comparisons, including general spectrotemporal processing for sound recognition Köppl and Carr 2003).…”

“…The two anatomically distinct cochlear nuclei, nucleus magnocellularis (NM) and nucleus angularis (NA), each receive information from the auditory nerve and specialize for encoding timing information (NM) and intensity, or sound level, information (NA) for the computation of sound location (Boord 1968;Carr and Boudreau 1991;Parks and Rubel 1978;Puelles et al 2007;Reyes et al 1994;Sullivan and Konishi 1984;Trussell 1999). Nucleus angularis is highly heterogeneous in terms of neuronal morphology, acoustic response types in vivo and intrinsic physiology in vitro, and has multiple ascending projections, suggesting that it performs multiple functions Fukui and Ohmori 2003;Häusler et al 1999;Krützfeldt et al 2010a;MacLeod and Carr 2007;Sachs and Sinnott 1978;Sato et al 2010;Soares and Carr 2001;Soares et al 2002;Wang and Karten 2010;Warchol and Dallos 1990). The present study was undertaken to better define the molecular characterization of neurons in NA.…”

Response Properties of Single Neurons in the Zebra Finch Auditory Midbrain: Response Patterns, Frequency Coding, Intensity Coding, and Spike Latencies

“…These areas have been well described both anatomically and physiologically in chicks and owls (Carr and Konishi 1988;Koppl 1997Koppl , 2001Koppl and Carr 2003;Parks and Rubel 1978;Rubel and Parks 1975;Sachs and Sinnott 1978;Sullivan 1985;Takahashi and Konishi 1988;Warchol and Dallos 1990). One study examined the frequency tuning found in NM and NA of a songbird, the red-winged blackbird (Sachs and Sinnott 1978). Some basic response characteristics are shared between MLd and the cochlear nuclei of other birds.…”

“…Figure 9 shows examples of complex tuning curves. Although some cells showed nonmonotonic responses at CF (see following text), no closed tuning curves [also called type IV (Sachs and Sinnott 1978;Young and Brownell 1976) The relationship between threshold and tuning curve shape was examined by calculating a Q 10 and Q 30 for each cell (Fig. 10).…”

Effects of Interaural Intensity Difference on the Processing of Interaural Time Difference in the Owl’s Nucleus Laminaris

“…NM neurons lack dendrites and contain end bulbs of Held, whereas NA neurons have dendrites and bouton-type synapses (Parks, 1981;Jhaveri and Morest, 1982;Takahashi and Konishi, 1988a;Carr and Boudreau, 1993). NM neurons show phase locking, whereas NA neurons do not except for very low frequencies (Sachs and Sinnott, 1978;Sullivan and Konishi, 1984a;Konishi et al, 1985;Warchol and Dallos, 1990). The time-and intensity-processing pathways converge in the inferior colliculus, where neurons selective for combinations of ITD and IID are found.…”