Alteration of CaBP Expression Pattern in the Nucleus Magnocellularis following Unilateral Cochlear Ablation in Adult Zebra Finches

Abstract

Songbirds have the rare ability of auditory-vocal learning and maintenance. Up to now, the organization and function of the nucleus magnocellularis (NM), the first relay of the avian ascending auditory pathway is largely based on studies in non-vocal learning species, such as chickens and owls. To investigate whether NM exhibits different histochemical properties associated with auditory processing in songbirds, we examined the expression patterns of three calcium-binding proteins (CaBPs), including calretinin (CR), parvalbumin (PV) and calbindin-D28k (CB), and their relations to auditory inputs in NM in adult zebra finches. We found enriched and co-localized immunostaining of CR, PV and CB in the majority of NM neurons, without neuronal population preference. Furthermore, they were sensitive to adult deafferentation with differential plasticity patterns. After unilateral cochlear removal, CR staining in the ipsilateral NM decreased appreciably at 3 days after surgery, and continued to decline thereafter. PV staining showed down-regulation first at 3 days, but subsequently recovered slightly. CB staining did not significantly decrease until 7 days after surgery. Our findings suggest that the three CaBPs might play distinct roles in association with auditory processing in zebra finches. These results are in contrast to the findings in the NM of chickens where CR is the predominant CaBP and deafferentation had no apparent effect on its expression. Further extended studies in other avian species are required to establish whether the difference in CaBP patterns in NM is functionally related to the different auditory-vocal behaviors.

Distinct Neural Properties in the Low-Frequency Region of the Chicken Cochlear Nucleus Magnocellularis

“…Expression of various calcium-binding proteins in auditory neurons displays cell-type specificity and species variation ( Takahashi et al, 1987 ; Rogers, 1989 ; Li et al, 2013 ). In chickens, it is reported that all neurons in NM express calretinin but not parvalbumin, two EF-hand calcium binding proteins ( Rogers, 1987, 1989 ).…”

“…In addition, we found parvalbumin-expressing neurons in NM including NMc1 and NMc2. Similarly, the majority, if not all, of NM neurons coexpress these two calcium-binding proteins in the zebra finch ( Li et al, 2013 ), emu ( MacLeod et al, 2006 ), and owl ( Takahashi et al, 1987 ; Kubke et al, 1999 ). Calretinin and parvalbumin have fast and slow calcium-binding kinetics, respectively, which are fine-tuned by instantaneous intracellular calcium concentration.…”

Thalamostriatal and cerebellothalamic pathways in a songbird, the Bengalese finch

“…Anti-parvalbumin, EMD Millipore MAB1572, mouse monoclonal, was raised against parvalbumin purified from frog muscle, and in Western blots yields a band at 12kDa (the weight of parvalbumin). The antibody shows specific immunoreactivity with parvalbumin expressing interneurons (McKenna et al, 2013) and has been used to label such neurons in songbirds (Li et al, 2013). It has previously been shown that one cell type in Area X expresses parvalbumin and that Area X shows higher immunoreactivity for parvalbumin in its neuropil than the surrounding medial striatum (Braun, Scheich, Schachner, & Heizmann, 1985; Carrillo & Doupe, 2004; Reiner, Laverghetta, Meade, Cuthbertson, & Bottjer, 2004)…”

Clustered organization and region‐specific identities of estrogen‐producing neurons in the forebrain of Zebra Finches (Taeniopygia guttata)

“…Our staining pattern with the antibody in zebra finch tissue matches that of a previously reported distribution using a specific antibody raised against the chicken calbindin protein (Pinaud, Fortes, Lovell, & Mello, ) Anti‐parvalbumin antibody (Millipore, MAB1572, RRID: AB_2174013) was raised against parvalbumin protein purified from frog muscle (manufacturer information). The specificity of the antibody has been shown using western blot (Li et al, ). Our staining pattern in the zebra finch is identical to previously reported distributions using a different specific antibody (Wild, Williams, Howie, & Mooney, ). Anti‐post‐synaptic density protein 95 (PSD95) antibody (Millipore, MAB 1596, RRID: AB_2092365) was raised against recombinant rat PSD95 (manufacturer information).…”