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Full-Text Articles in Life Sciences

How Do Adult Songbirds Learn New Sounds? Using Neuromodulators To Probe The Function Of The Auditory Association Cortex, Matheus Macedo-Lima Jul 2020

How Do Adult Songbirds Learn New Sounds? Using Neuromodulators To Probe The Function Of The Auditory Association Cortex, Matheus Macedo-Lima

Doctoral Dissertations

The ability to associate sounds and outcomes is vital in the life history of many species. Animals constantly assess the soundscape for cues associated with threats, competitors, allies, mates or prey, and experience is crucial for those associations. For vocal learning species such as humans and songbirds, learning sounds (i.e. perception and association learning) is also the first step in the process of vocal learning. Auditory learning is thought to depend on high-order cortical brain structures, where sounds and meaning are bound. In songbirds, the caudomedial nidopallium (NCM) is part of the auditory association cortex and is known to be …


Neurogenesis Is Altered Between And Across Brain Regions After Neurodegeneration And Injury, Alice Perez Sep 2019

Neurogenesis Is Altered Between And Across Brain Regions After Neurodegeneration And Injury, Alice Perez

Dissertations, Theses, and Capstone Projects

Adult neurogenesis is the addition of new neurons in the adult brain. In mammals, neurogenesis is largely restricted to the hippocampus and olfactory bulb, which underlie learning, memory, and olfaction. In songbirds, new neurons are incorporated into telencephalic regions that subserve the production, perception, and maintenance of song. Studies of the regulation of neurogenesis have exclusively focused on a single brain region and within a single hemisphere. Interestingly, it has yet to be investigated whether there are correlations between numbers of new neurons across regions and hemispheres within the same animal. Here we examined these differences in a rat model …


Acute Estrogen Synthesis And Action In The Auditory Cortex Of Developing Male Zebra Finches (Taeniopygia Guttata), Daniel Vahaba Jul 2019

Acute Estrogen Synthesis And Action In The Auditory Cortex Of Developing Male Zebra Finches (Taeniopygia Guttata), Daniel Vahaba

Doctoral Dissertations

Birdsong, as with human speech, is learned during an age- and experience-dependent sensitive period early in life. Songbirds must first memorize their parents’ song during a sensory phase, then refine their own burgeoning vocalizations to match the auditory memory of their parents’ song during a sensorimotor phase. While the error-correction aspect of the sensorimotor phase of song learning is comparatively well understood, it is largely unknown how auditory memories are formed and how auditory processing may change across development to facilitate song memorization. The songbird caudomedial nidopallium (NCM) is a brain region that encodes complex communication signals like song and …


An Investigation Of Vocal Learning Propensity In Zebra Finch (Taeniopygia Guttata), Tatsuya Hayashi Aug 2018

An Investigation Of Vocal Learning Propensity In Zebra Finch (Taeniopygia Guttata), Tatsuya Hayashi

Theses and Dissertations

The investigator attempted to predict the vocal learning propensity from either family pedigree or early vocal babbling (subsong). Pedigree trees suggest the possibility that vocal learning ability may depend on family. We failed to predict vocal learning propensity from subsong, but suggested that subsong may influence vocal learning outcome.


Song Rhythm Development In Zebra Finches, Julia Hyland Bruno Sep 2017

Song Rhythm Development In Zebra Finches, Julia Hyland Bruno

Dissertations, Theses, and Capstone Projects

This dissertation investigates song-rhythm learning in songbirds. Songbirds have been studied extensively in mechanistic investigations into the sensorimotor underpinnings of the cultural transmission of learned vocalizations. While several studies identified forebrain song-system neurons that generate rhythmic song patterns, we know little about how song rhythms are learned. The first part of the dissertation describes methods for detecting and analyzing birdsong rhythm patterns, and demonstrates their utility for identifying the role of song rhythms in social interactions. Results suggest that rhythm plasticity in zebra finch song may provide a potential vehicle for communication. Controlled song-learning experiments further found that developing zebra …


Adult Neurogenesis In Avian Auditory Cortex, Caudomedial Nidopallium (Ncm): Lateralization And Effects Of Statins, Shuk C. Tsoi Sep 2016

Adult Neurogenesis In Avian Auditory Cortex, Caudomedial Nidopallium (Ncm): Lateralization And Effects Of Statins, Shuk C. Tsoi

Dissertations, Theses, and Capstone Projects

In the first part of this paper, we investigated the basic relationship between learning, memory and adult neurogenesis using zebra finches. We found that in the auditory cortex, the left hemisphere had more new neurons than the right hemisphere. This lateralization was correlated with song learning and memory. In the second part, we used juvenile zebra finches as a model organism to study the effects of Lipitor on learning, memory and neurogenesis. We found that Lipitor impaired song learning and memory storage. Lipitor treatments also changed the morphology of new neurons and size of old neurons, suggesting statins may affect …


House Finches, Carpodacus Mexicanus: Hormones, Stress, And Song Control Regions, Katherine Olivia Ganster Dec 2012

House Finches, Carpodacus Mexicanus: Hormones, Stress, And Song Control Regions, Katherine Olivia Ganster

Master's Theses

Song production in songbirds is controlled by parts of the brain known as the song control regions (SCRs). During spring, gonads increase in size, males sing to attract mates, and SCRs become larger. This neuroplasticity is controlled by the change in day length and increased plasma testosterone (T) levels. Plasma T can be reduced by stress through the production of corticosterone (CORT), through the production of beta-endorphin, or through direct effects on the testes via the nervous system. We determined the T, estradiol, and CORT hormonal profiles of wild House Finches by capturing and sampling blood from the finches every …