;; Akemann W, Knopfel T. Interaction of Kv3 potassium channels and
;; resurgent sodium current influences the rate of spontaneous firing of
;; Purkinje neurons. J Neurosci. 2006 Apr 26;26(17):4602-12.

(nemo-model CaP

  ((input v 
	  (cai from ion-pools))
	     
   (const Vrest   = -68)
   (const celsius = 24)
   
   (const temp_adj = (pow (3 ((celsius - 22) / 10))))

   (defun ghk (v celsius ci co)
     (let ((F 96485.0) (R 8.3145))
       (let ((zeta ((2e-3 * F * v) / (R * (273.19 + celsius)))))
	 (if ((abs (1.0 - exp (neg (zeta)))) < 1e-6)
	     then (1e-6 * (2 * F) * (ci - (co * exp (neg (zeta)))) * (1.0 + (zeta / 2)))
	     else ((1e-6 * (2 * zeta * F) * (ci - (co * exp (neg (zeta))))) / (1.0 - exp (neg (zeta))))))))

   (component (type ion-channel) (name CaP)
	      
	      (component (type gate)
			 
			 ;; rate functions
			 (defun CaP_inf (v)  
			   (let ((cv  19)  (ck  5.5))
			     (1.0 / (1.0 + exp (neg ((v + cv) / ck))))))
			 
			 (defun CaP_tau (v)  
			   (if (v > -50) 
			       then (1e3 * (0.000191 + (0.00376 * pow ((exp (neg ((v + 41.9) / 27.8)))  2))))
			       else (1e3 * (0.00026367 + (0.1278 * exp (0.10327 * v))))))

			 (hh-ionic-gate 
			  (CaP  ;; ion name: exported variables will be of the form {ion}_{id}
			   (initial-m  (CaP_inf (Vrest)))
			   (m-power    1)
			   (h-power    0)
			   (m-inf      (CaP_inf (v)))
			   (m-tau      (CaP_tau (v) / temp_adj))))
			 
			 )

	      (component (type permeability)
			 (const pcabar_CaP  = 0.01667)
			 (const cao       = 2.4)
			 (pca_CaP        = (pcabar_CaP * ghk (v celsius cai cao)))
			 (output pca_CaP pcabar_CaP ))
	      
	      (component (type permeating-ion) (name ca) )
	      
	      
	      ) ;; end CaP current
	    
   ))