Behavioral Neuroscience Summers

Honey Bee Ecology and Behavior Honey Bee Neuroanatomy Fundamentals of Neurocircuitry Sensory Afferent input for Proboscis Extension

Gating Proboscis Extension Learning to Drink Conditioned Proboscis Extenstion Motor Neuron output for Proboscis Extension

Acetylcholine ACh Octopamine OA Integration: Honey Bee Conditioned Drinking

Honey Bee figures Honey Bee Conditioned Drinking Neurocircuitry end     Acronyms/Abbreviations

Honey Bee Conditioned Drinking
XIV. A Bee's First Foraging Trip  
	    
	A.	Arrival at a Flower - Inspection
    
		1. Flower specific nectar oder (+ flower odor)    
    
			a. enter Antennae placode sensilla
            
				i. diffuse through sensillum lymph           

			b. Bind to odorant binding proteins (OBP)

				i. directed diffusion
                
			c. OBP + odorant move to ORNs    
    
			d. OBP + odorant bind to olfactory receptor proteins (OR) on ORNs    
    
		2. triggers Antennae ORNs action potential   
 
		3. ORN AP to antennal lobe glomeruli

			a. ORN ACh à nAChR on AL PN 

		4. AL PN à SEG proboscis-related motor neuron			
            
			a. AL ACh à nAChR on mandible abductor (M8) neuron            

				i. ORN ð AL PN ð ñ SEB M8 neuron ð M8 = reflexive motor pathway            

			b. M8 neuron ACh à nAChR on mandible abductor muscle à contracts              

				i. mandibles spread
                            
 		5. proboscis extend mechanically           
            
            
	B. Specific Nectar-Odor pairing            
            
		1. ORN à AChà nAChR AL PN à AChà nAChR MB KC

			a.  ORN à AL PN à LH

			b. via lAPT + mAPT

				i. lAPT: AL à LH à MB KC
                
				ii. mAPT: AL à MB KC à LH

			c. odor signal NOT sufficient to potentiate downstream effector neurons 

				i. not enough alone to trigger Pe-1
                
		2.	Extended proboscis/glossa (ORN/AL/M8 neuron) enters nectar

			a. Nectar sucrose activates chemoreceptors on GRN

			b. GRN action potentialà ACh à nAChR on VUMmx1
            
				i. GRN AP à ACh à nAChR AL PN àACh  

			c. AL PN ACh à nAChR on VUMmx1 

				i. VUMmx1 à OA à AmOA1

		3. Binds to octopamine receptor AmOA1 in AL
        
        	a. OA à AmOA1 LH

			b. OA à AmOA1 MB KC
	
		4. Coincident ACh and OA signalling in MB KC
        
			a. also in AL and LH
                        
    C. Gating Coincidence output - CS + US pairing produces: 

		1. MB KC nAChR ð ñ Vm ð ñ VGCC ð ñ Ca++
        
		2. MB KC AmOA1 à GPq11 à IP3 à ⇧ Ca++

		3. ññ Ca++ ð ññ rutAC

			a. ññ rutAC ð ññ cAMP ð ññ PKA ð ññ pAmCREB ð ññ CRE activation

				i. ññ CRE ð ññ ubiquitin hydrolase ð ññ PKA

					1) ññ PKA ð ññ pAmCREB ð ññ CRE
 
 		4. ññ CRE ð ññ C/EBP ð ññ  EF1a 

			a. ññ formation of new synapses

			b. similar coincidence effects at LH

		5. New synapses potentiates Pe-1 signal output

			a. and LH signal output

		6. Pe-1 and LH projections converge on the SEG M8 motor neurons

			a. doubles the signal strength on M8 neurons 

				i. another kind of potentiation 
                
			b. AmOA1-facilitated PE-1 + LH potentiation adds to the strength of convergence  
                
				i. ññññ M8 neuron potentiation
 
 			c. proboscis stays extended
                                                
 	D. Drinking  is enabled by continued proboscis/glossa extension    
        
      
	E. Coincidence + Aversion
    
		1. CS + US convergence: ORN ð AL PN ð LH + MB KC    
    
			a. GRN ð SEG Maxillary ganglion VUMmx1 ðAL PN + LH + MB KC
			
 		2. Toxin: GRN "deterent" ð AL DA PN ð a lobe MB GABAergic neurons           
            
 			a. GRN "deterent" ð AL DA ð AmD2 aMB GABA ðGABAA ð ò MB KC
            
			b. GRN "deterent" ð AL inhibitory GABAergic local neurons (LN)           
            
				i. GRN "deterent" ð AL LN  ð GABA ð GABAA ð ò AL PN				            
            
		3. ð weak or blocked AL PN signal
        
		4. ð weak or blocked MB KC signal

			a. ð weak or blocked LH signal
        
		5. NO Pe-1 or LH potentiation
        
			a. no Pe-1 + LH potentiation of SEB M8 neuron        	    

				i. in Mandibular ganglion

		6. labium and glossa retractor muscles M17, M20

			a. can remove glossa/proboscis from toxic nectar