Calcium-binding protein distributions and fiber connections of the nucleus accumbens in the pigeon (Columba livia).

Until recently, the exact location of the avian nucleus accumbens within the basal forebrain had not been well established (Reiner et al. [2004] J Comp Neurol 473:377-414). While a number of previous studies have shown afferents and efferents of the presumptive "nucleus accumbens," detailed and accurate connection patterns of this newly recognized area are still lacking.

Avian visual behavior and the organization of the telencephalon.

Birds have excellent visual abilities that are comparable or superior to those of primates, but how the bird brain solves complex visual problems is poorly understood. More specifically, we lack knowledge about how such superb abilities are used in nature and how the brain, especially the telencephalon, is organized to process visual information. Here we review the results of several studies that examine the organization of the avian telencephalon and the relevance of visual abilities to avian social and reproductive behavior.

Female stimuli trigger gene expression in male pigeons.

The immediate early gene zenk encodes transcriptional regulators and is believed to be one of the first steps in the formation of long-term memories associated with a given stimulus. In this study, we investigated the expression of ZENK protein product in brain regions that are likely involved in the processing of social stimuli, such as a potential mate. Male pigeons (Columba livia) were exposed to one of the following: (1) a live female pigeon, (2) a video playback of a female pigeon, (3) a video playback of a female cockatoo, or (4) an empty stimulus chamber.

Olfaction and olfactory epithelium in mice treated with zinc gluconate.

Objective: We assessed whether a nasal spray containing zinc gluconate (ZG) compromises the integrity of olfactory epithelium and olfactory function.

Methods: Axonal transport of horseradish peroxidase from olfactory epithelium to the olfactory bulb was studied in 2- to 21-day survival mice given intranasal injections of 2, 8, or 50 microL of ZG (approximately 4, 15, and 94 times the equivalent recommended human dose). Other similarly treated mice were tested using precision olfactometry to detect and discriminate odors.

Avian brains and a new understanding of vertebrate brain evolution.

We believe that names have a powerful influence on the experiments we do and the way in which we think. For this reason, and in the light of new evidence about the function and evolution of the vertebrate brain, an international consortium of neuroscientists has reconsidered the traditional, 100-year-old terminology that is used to describe the avian cerebrum. Our current understanding of the avian brain - in particular the neocortex-like cognitive functions of the avian pallium - requires a new terminology that better reflects these functions and the homologies between avian and mammalian brains.

Revised nomenclature for avian telencephalon and some related brainstem nuclei.

The standard nomenclature that has been used for many telencephalic and related brainstem structures in birds is based on flawed assumptions of homology to mammals. In particular, the outdated terminology implies that most of the avian telencephalon is a hypertrophied basal ganglia, when it is now clear that most of the avian telencephalon is neurochemically, hodologically, and functionally comparable to the mammalian neocortex, claustrum, and pallial amygdala (all of which derive from the pallial sector of the developing telencephalon). Recognizing that this promotes misunderstanding of the functional organization of avian brains and their evolutionary relationship to mammalian brains, avian brain specialists began discussions to rectify this problem, culminating in the Avian Brain Nomenclature Forum held at Duke University in July 2002, which approved a new terminology for avian telencephalon and some allied brainstem cell groups.

The Avian Brain Nomenclature Forum: Terminology for a New Century in Comparative Neuroanatomy.

Many of the assumptions of homology on which the standard nomenclature for the cell groups and fiber tracts of avian brains have been based are in error, and as a result that terminology promotes misunderstanding of the functional organization of avian brains and their evolutionary relationship to mammalian brains. Recognizing this problem, a number of avian brain researchers began an effort to revise the terminology, which culminated in the Avian Brain Nomenclature Forum, held at Duke University from July 18 to 20, 2002. In the new terminology approved at this Forum, the flawed conception that the telencephalon of birds consists nearly entirely of a hypertrophied basal ganglia has been purged from the telencephalic terminology, and the actual parts of the basal ganglia and its brainstem afferent cell groups have been given names reflecting their now evident homologies.