scholarly journals Characterization of the olfactory system in Apis dorsata, an Asian honey bee

2018 ◽  
Author(s):  
Sandhya Mogily ◽  
Meenakshi VijayKumar ◽  
Sunil Kumar Sethy ◽  
Joby Joseph

AbstractThe European honeybee, Apis mellifera is the most common insect model system for studying learning and memory. We establish that the olfactory system of Apis dorsata, an Asian species of honeybee as an equivalent model to Apis mellifera to study physiology underlying learning and memory. We created an Atlas of the antennal lobe and counted the number of glomeruli in the antennal lobe of Apis dorsata to be around 165 which is similar to the number in the other honey bee species Apis mellifera and Apis florea. Apis dorsata was found to have five antenno-cerebral tracts namely mACT, lACT and 3 mlACTS which appear identical to Apis mellifera. Intracellular recording showed that the antennal lobe interneurons exhibit temporally patterned odor-cell specific responses. The neuritis of Kenyon cells with cell bodies located in a neighborhood in calyx retain their relative neighborhoods in the peduncle and alpha lobe forming a columnar organization in the mushroom body. Alpha lobe and the calyx of the mushroom body were innervated by extrinsic neurons with cell bodies in the lateral protocerebrum. A set of GABA positive cells in the lateral protocerebrum send their neurites towards alpha-lobe. Apis dorsata was amenable to olfactory conditioning and showed good learning and memory retention at 24 hours. They were amenable to massed and spaced conditioning and could distinguish trained odor from an untrained novel odor.

2020 ◽  
Vol 64 (1) ◽  
pp. 123-130
Author(s):  
Gordana Glavan

AbstractOrganophosphate insecticides are known to inhibit the activity of enzyme acetylcholinesterase. They affect olfactory learning and memory formation in honeybees. These insecticides cause mushroom body inactivation in honeybees, but their influence on other brain regions involved in olfactory perception and memory is unknown. The goal of this study was to study the effects of organophosphate insecticide diazinon on carnolian honeybee (Apis mellifera carnica) acetylcholinesterase activity in the olfactory brain regions of antennal lobe, mushroom body and lateral procerebrum (lateral horn). The lamina, medulla and lobula of optic lobes were also analyzed. The level of acetylcholinesterase activity was visualized using the histochemical staining method. Densitometric analysis of histochemical signals indicated that diazinon inhibited acetylcholinesterase activity only in the lip of calyces of mushroom body, but not in other analyzed olfactory regions, antennal lobe and lateral procerebrum. The visual brain system optic lobes were also unaffected. This is in accordance with the literature reporting that mushroom body is the main brain center for olfactory learning and memory formation in honeybees.


2018 ◽  
Vol 107 ◽  
pp. 250-256 ◽  
Author(s):  
Julie A. Mustard ◽  
Valerie Alvarez ◽  
Sofy Barocio ◽  
Jamie Mathews ◽  
Alexander Stoker ◽  
...  

2018 ◽  
Author(s):  
Meenakshi Vijaykumar ◽  
Sandhya Mogily ◽  
Aparna Dutta-Gupta ◽  
Joby Joseph

AbstractCapacity and condition under which lateral transfer of olfactory memory is possible in insects are still debated. Here we present evidence consistent with lack of ability to transfer olfactory associative memory in two species of honeybees, Apis mellifera and Apis dorsata in a PER associative conditioning paradigm where the untrained antenna is blocked by an insulating coat. We show that the olfactory system on each side of the bee can learn and retrieve independently and the retrieval using the antenna on the side contralateral to the trained one is not affected by the training. Recreating the paradigm in which the memory on the contralateral side has been reported at three hours after training we see that the memory is available on the contralateral side immediately after training and moreover, training with trained side antenna coated with insulator does not prevent learning, pointing to a possible insufficiency of block of odor stimuli in this paradigm. Bee does not learn the odor stimuli applied to one side alone as a stimulus different from odor presented to both sides. Moreover the behaviour of the bee as a whole can be predicted if the sides are assumed to learn and store independently and the organism as a whole is able to retrieve the memory if either of the sides have learned.Summary StatementThe two halves of honeybee brain store and retrieve olfactory associative memories independently.


Author(s):  
Philipp Schlegel ◽  
Alexander Shakeel Bates ◽  
Tomke Stürner ◽  
Sridhar R. Jagannathan ◽  
Nikolas Drummond ◽  
...  

AbstractThe hemibrain connectome (Scheffer et al., 2020) provides large scale connectivity and morphology information for the majority of the central brain of Drosophila melanogaster. Using this data set, we provide a complete description of the most complex olfactory system studied at synaptic resolution to date, covering all first, second and third-order neurons of the olfactory system associated with the antennal lobe and lateral horn (mushroom body neurons are described in a parallel paper, (Li et al., 2020)). We develop a generally applicable strategy to extract information flow and layered organisation from synaptic resolution connectome graphs, mapping olfactory input to descending interneurons. This identifies a range of motifs including highly lateralised circuits in the antennal lobe and patterns of convergence downstream of the mushroom body and lateral horn. We also leverage a second data set (FAFB, (Zheng et al., 2018)) to provide a first quantitative assessment of inter- versus intra-individual stereotypy. Complete reconstruction of select developmental lineages in two brains (three brain hemispheres) reveals striking similarity in neuronal morphology across brains for >170 cell types. Within and across brains, connectivity correlates with morphology. Notably, neurons of the same morphological type show similar connection variability within one brain as across brains; this property should enable a rigorous quantitative approach to cell typing.


2020 ◽  
Vol 11 ◽  
Author(s):  
Gerd Bicker ◽  
Michael Stern

Regeneration after injury is accompanied by transient and lasting changes in the neuroarchitecture of the nervous system and, thus, a form of structural plasticity. In this review, we introduce the olfactory pathway of a particular insect as a convenient model to visualize neural regeneration at an anatomical level and study functional recovery at an electrophysiological level. The olfactory pathway of the locust (Locusta migratoria) is characterized by a multiglomerular innervation of the antennal lobe by olfactory receptor neurons. These olfactory afferents were axotomized by crushing the base of the antenna. The resulting degeneration and regeneration in the antennal lobe could be quantified by size measurements, dye labeling, and immunofluorescence staining of cell surface proteins implicated in axonal guidance during development. Within 3 days post lesion, the antennal lobe volume was reduced by 30% and from then onward regained size back to normal by 2 weeks post injury. The majority of regenerating olfactory receptor axons reinnervated the glomeruli of the antennal lobe. A few regenerating axons project erroneously into the mushroom body on a pathway that is normally chosen by second-order projection neurons. Based on intracellular responses of antennal lobe output neurons to odor stimulation, regenerated fibers establish functional synapses again. Following complete absence after nerve crush, responses to odor stimuli return to control level within 10–14 days. On average, regeneration of afferents, and re-established synaptic connections appear faster in younger fifth instar nymphs than in adults. The initial degeneration of olfactory receptor axons has a trans-synaptic effect on a second order brain center, leading to a transient size reduction of the mushroom body calyx. Odor-evoked oscillating field potentials, absent after nerve crush, were restored in the calyx, indicative of regenerative processes in the network architecture. We conclude that axonal regeneration in the locust olfactory system appears to be possible, precise, and fast, opening an avenue for future mechanistic studies. As a perspective of biomedical importance, the current evidence for nitric oxide/cGMP signaling as positive regulator of axon regeneration in connectives of the ventral nerve cord is considered in light of particular regeneration studies in vertebrate central nervous systems.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Lise R. Charbonneau ◽  
Neil Kirk Hillier ◽  
Richard E. L. Rogers ◽  
Geoffrey R. Williams ◽  
Dave Shutler

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